[DENCOUCH]

Yes, you will feel a difference in performance... tires will most likely break traction between shifts. and your mileage may slip.

I forgot to mention that you will have to have your speedo re-calibrated, but that is easy.

Have fun.

and relive the feeling of of being pushed back into you seat when you step on it.

[zzarich]

Originally Posted by DENCOUCH

Yes, you will feel a difference in performance... tires will most likely break traction between shifts. and your mileage may slip.

I forgot to mention that you will have to have your speedo re-calibrated, but that is easy.

Have fun.

and relive the feeling of of being pushed back into you seat when you step on it.

in the performance aspect whats the difference if just swaped the gears and not the rear end? this much money isnt a real problem for me to get so the easier it is for me to do is the way i will go

[DENCOUCH]

If you look at Summits price on gears, it will cost about $190 bucks for a performance ring & pinion gear set. The install kit is another $90 bucks.

You will need a dial indicator with a magnetic base to check the clearances & lash. You will need a torque wrench graduated in inch/pounds to set the correct preload on the pinion bearing. This required that you tighten the pinion gland nut to 180 lbs of torque, but not so tight that the crush sleeve is over tightened so that the pinion will turn with about 11 in/lb torque. If you over tighten it, then press out the pinion gear and load in another crush sleeve... try again.

Faster & cheaper to shop for a used rear end with all of this already done for ya.

No difference if you find a 3.37 rear end already to go, or install your own 3.37 gears... performance would be the same.

Check & see what gear set you have ... that will give you an idea of how much better your car will scoot if you select a lower gear set.

[cobalt327]

I'm wondering what condition and/or state of tune the engine is now. Have you taken it down the quarter mile yet?

I put a BONE STOCK Olds 455 out of a wagon into a barge-sized '76 Cutlass and it went high 13's w/a single side rear end w/2.73:1 gears, cast iron exhaust and intake manifolds. The only "work" done to it was to rebuild the Q-jet and recurve the distributor along w/a new timing set. It would burn the tire for a city block- and that is not an exaggeration!

If this doesn't sound like you- then you better start w/a compression test, a vacuum test and possibly a leakdown test to see what the condition of the engine is before you go any further.

If the tests all look good, then do a complete tune up and be sure the carb is working as it should. Recurve the distributor and see what you have after doing those few things. Because I can tell you, it should be running pretty damn good- even stock.

[zzarich]

Originally Posted by DENCOUCH

If you look at Summits price on gears, it will cost about $190 bucks for a performance ring & pinion gear set. The install kit is another $90 bucks.

You will need a dial indicator with a magnetic base to check the clearances & lash. You will need a torque wrench graduated in inch/pounds to set the correct preload on the pinion bearing. This required that you tighten the pinion gland nut to 180 lbs of torque, but not so tight that the crush sleeve is over tightened so that the pinion will turn with about 11 in/lb torque. If you over tighten it, then press out the pinion gear and load in another crush sleeve... try again.

Faster & cheaper to shop for a used rear end with all of this already done for ya.

No difference if you find a 3.37 rear end already to go, or install your own 3.37 gears... performance would be the same.

Check & see what gear set you have ... that will give you an idea of how much better your car will scoot if you select a lower gear set.

how would i find out what gears i have?

[zzarich]

Originally Posted by cobalt327

I'm wondering what condition and/or state of tune the engine is now. Have you taken it down the quarter mile yet?

I put a BONE STOCK Olds 455 out of a wagon into a barge-sized '76 Cutlass and it went high 13's w/a single side rear end w/2.73:1 gears, cast iron exhaust and intake manifolds. The only "work" done to it was to rebuild the Q-jet and recurve the distributor along w/a new timing set. It would burn the tire for a city block- and that is not an exaggeration!

If this doesn't sound like you- then you better start w/a compression test, a vacuum test and possibly a leakdown test to see what the condition of the engine is before you go any further.

If the tests all look good, then do a complete tune up and be sure the carb is working as it should. Recurve the distributor and see what you have after doing those few things. Because I can tell you, it should be running pretty damn good- even stock.

i havent taken down the quarter or anything like that. what kind of place does tests like that? and when u say tune up, u mean just like u would tune up a newer car or what?

[zzarich]

Originally Posted by DENCOUCH

If you look at Summits price on gears, it will cost about $190 bucks for a performance ring & pinion gear set. The install kit is another $90 bucks.

You will need a dial indicator with a magnetic base to check the clearances & lash. You will need a torque wrench graduated in inch/pounds to set the correct preload on the pinion bearing. This required that you tighten the pinion gland nut to 180 lbs of torque, but not so tight that the crush sleeve is over tightened so that the pinion will turn with about 11 in/lb torque. If you over tighten it, then press out the pinion gear and load in another crush sleeve... try again.

Faster & cheaper to shop for a used rear end with all of this already done for ya.

No difference if you find a 3.37 rear end already to go, or install your own 3.37 gears... performance would be the same.

Check & see what gear set you have ... that will give you an idea of how much better your car will scoot if you select a lower gear set.

would 3.42 gears be pretty much the same?

[FmrStrtracer]

3.42's would be a great ratio.

Who put the 455 in the car, and whats done to it besides the intake carb and headers?
What type of distributor? are the plugs, wire, cap and rotor in good shape?
Where is the timing set? Have you adjusted the timing or the carb to get more performance out of the engine?
455's have a long stroke(4.25), and make alot of torque, even with stock gearing(2.56 or 2.73's mostlikely), the car should still be able to accelerate quite quickly, if youre getting traction.
What transmission is in the car?

[zzarich]

Originally Posted by FmrStrtracer

3.42's would be a great ratio.

Who put the 455 in the car, and whats done to it besides the intake carb and headers?
What type of distributor? are the plugs, wire, cap and rotor in good shape?
Where is the timing set? Have you adjusted the timing or the carb to get more performance out of the engine?
455's have a long stroke(4.25), and make alot of torque, even with stock gearing(2.56 or 2.73's mostlikely), the car should still be able to accelerate quite quickly, if youre getting traction.
What transmission is in the car?

the 455 is stock andit has the turbo 400 transmission, the only other thing is a flowmaster exhaust system, and traction isnt to good considering they spinalmost everytime i turn. i havent adjusted anything like that, what would be good to start with?

[Thumpin455]

DO NOT put 3.73 or 4.10 gears in it! It is NOT a small chevy. You have a 4.25" stroke crank, that is not an engine that needs RPM. Also the Olds has a rocker arm setup that doesnt like more than 5500 rpm. You will go slower, burn more fuel, and do little more than beat your engine up. The most you want to go is 3.55, and really 2.73-3.08 works just fine with a 455.

A set of headers, some tuning and a mild stall if its an automatic will really wake it up. No more than 2400 on the stall if its an auto.

What cam you can run depends on what heads it has, if it has J heads you will be a bit more limited because of the lower compression and ports that arent quite as good. If you have A, C, or E heads then you will have compression that might be too high for pump gas. The rocker arms are also something you have to consider with the cam. One with less than .500 lift and 220-228 intake/224-230 exhaust duration would work nice and not mess up the geometry bad enough you will need new rockers and machine work to the heads.

Stay away from single plane intakes, it isnt a small chevy. A stock non EGR intake is better than any single plane. I would go to a Holley or preferably a Qjet instead of the E carb.

Like the other guys said, what is it in, what trans does it have, and tell us what letter is cast in the ends of the heads adjacent to the exhaust ports? If its a number its a small Olds, letters are on the 400/425, and 455.

[mud bros]

my only reasoning behind 373-410 gears would be the fact his olds will probably have 28+ inch tall rear tires.

my stock big block shop truck is verry happy with 410s even on the hwy but i have near 30in tall tires

your totally correct that 355ish would be more appropriate for a engine that will turn less than 5000 especially if you have reduced the tire size from stock

[zzarich]

Originally Posted by Thumpin455

DO NOT put 3.73 or 4.10 gears in it! It is NOT a small chevy. You have a 4.25" stroke crank, that is not an engine that needs RPM. Also the Olds has a rocker arm setup that doesnt like more than 5500 rpm. You will go slower, burn more fuel, and do little more than beat your engine up. The most you want to go is 3.55, and really 2.73-3.08 works just fine with a 455.

A set of headers, some tuning and a mild stall if its an automatic will really wake it up. No more than 2400 on the stall if its an auto.

What cam you can run depends on what heads it has, if it has J heads you will be a bit more limited because of the lower compression and ports that arent quite as good. If you have A, C, or E heads then you will have compression that might be too high for pump gas. The rocker arms are also something you have to consider with the cam. One with less than .500 lift and 220-228 intake/224-230 exhaust duration would work nice and not mess up the geometry bad enough you will need new rockers and machine work to the heads.

Stay away from single plane intakes, it isnt a small chevy. A stock non EGR intake is better than any single plane. I would go to a Holley or preferably a Qjet instead of the E carb.

Like the other guys said, what is it in, what trans does it have, and tell us what letter is cast in the ends of the heads adjacent to the exhaust ports? If its a number its a small Olds, letters are on the 400/425, and 455.

its in a 72 cutlass supreme, turbo 400 transmisson and the other stuff i cant find and when u say tune up does that mean like take it in to shop for a tune up like a newer car or what?

[FmrStrtracer]

Originally Posted by zzarich

its in a 72 cutlass supreme, turbo 400 transmisson and the other stuff i cant find and when u say tune up does that mean like take it in to shop for a tune up like a newer car or what?

If you dont know how to tune an engine, then yes, you'll need to find a shop that knows how to work on older cars and pay them to do a performance tune up.
If you cant do a tune up, then you probably would be lost trying to install the rear gears, so again, find a shop that installs ring and pinions and get an estimate. If the car doesnt have a posi unit, you'll want to add that while theyre installing the ring and pinion, otherwise you will be stuck with a one-wheel-peel everytime you punch the throttle.

You are going to find that its quite expensive to modify a car if you have to pay someone to do all the work for you. Id suggest you wait with the upgrades, and take a basic automotive class to learn how to work on your car yourself(college or adult ed. nite classes)
Id also suggest you buy a Helm's Chassis Service Manual for your car, they are available from numerous places on the www. These are copies of the exact same manual the dealer Techs used when your car was new, every procedure is spelled out in text and pictures to walk you thru repairing your car.
Also, a 72 Cutlass Supreme with a factory 455 is not that common of a car(most had 350's, or were fast back Cutlass S models), can you post the first 6 digits of your vin for decoding?
There is a body build tag located on the drivers side cowl(under the hood), that will also list info about when and where you car was made, and possibly some option codes for how your car was originally ordered.(Color, interior style, A/C,etc)

[cobalt327]

Originally Posted by zzarich

when u say tune up does that mean like take it in to shop for a tune up like a newer car or what?

It basically means to replace the parts that wear and/or deteriorate over time. This can be done by you, providing you have the tools, a place to work (preferrably under a roof), time and inclination to learn the procedures if you don't know them already. There WILL be a fairly steep learning curve, but nothing that cannot be accomplished if you're willing to learn.

Otherwise, there's no shame in admitting it may be above your abilities or any of if the other things mentioned above are lacking at this point. If this is the case, look for a shop that you can trust, hopefully one that'll let you watch and maybe participate so the next time you'll be in a better position to do some or all of the work yourself.

Some things that will be done or replaced during a tune up (NOT all-inclusive):
• plugs
• plug wires
• distributor cap and rotor
• replace vacuum hoses/lines
• PCV valve
• air and fuel filters
• set the timing- both initial and total.
• recurve the ignition advance. This is done by changing the springs that control the centrifugal weights. It may require you to limit the amount of vacuum advance that the canister on the distributor supplies. You want about 10° to about 15° max from the vacuum advance. More on all this below.
• adjust the carb to give the highest vacuum at idle, or highest idle speed. If the carb is leaky or the idle mixture screws unresponsive, etc. it may be time for a rebuild.

From a previous post on ignition timing:

You should verify that what you are seeing at the damper and timing tab for TDC is actually TDC.
DETERMINING TDC will allow you to be sure the timing tab and damper are correctly indicating TDC.

MAKE A TIMING TAPE to see what the total timing is, w/o needing to use a dial back timing light. You can also buy a timing tape, they're not very expensive. The problem is if you have a different diameter damper than what the timing tape is made for.

Be sure the advance plate is free to move, w/o binding or friction. HERE'S an exploded view of an HEI distributor. THIS is a description of an HEI rebuild.

I would recommend that you use the vacuum advance, hooked to manifold vacuum. It should be limited to around 10° of added advance, but no more than about 15°. This will help keep the carb primary blades from being opened too far to get the idle speed where it needs to be. If the blades are opened too far, the idle quality and off idle response will not be good.

You may well need an adjustable vacuum advance to get the advance at a low enough vacuum, given the lack of idle vacuum you now have. Using the vacuum advance should help bring up the idle vacuum as well.

If the vacuum advance you have comes in OK but gives too much advance, you will need to physically limit the vacuum advance can's travel w/a vacuum advance limiter plate like the Crane #99619-1, #99619 Instructions. Or you can easily make one.

Crane has an adjustable vacuum advance can kit- Crane #99600-1, #99600-1 Instructions.

The Accel #31035, #31035 Instructions is another adjustable vacuum advance can for the GM HEI. Comes w/instructions and tool.