[pittbull7934]

I have a 383 stroker, here are the specs on it:

The rods are 5.700 stroke (a little longer) Molly rings with forged flattop pistons, the whole bottom end was balanced.

The heads are from a 350 engine they have had a 3 angle grind job on them, and had stronger over sized valves installed with bigger springs for a higher lift cam. Up to 540 lift. Manley valves 2.02 intake valves 1.60 exhaust valves. The cc of the head i believe are 68 which would make the compression ratio 9.7:1.

Crower cam grind: 288hdp lobe center 112 intake 288 exhaust 296 duration @ .050 intake 234 exhaust 246 gross lift .497 .504 crower hyd lifters and single springs for the cam crower aluminum roller rocker arms ARP stud kits for heads and journals ARP bolt kits for everything else (intake, exhaust, carb, timing cover ect ect).

High flow oil pump with extra volume oil pan ( i think it takes 8 qts)

edelbrock timing adjustable timing chain.

edelbrock performer RPM air gap manifold

Accel HEI distributer with HEI unit

Accel 8.8mm racing wires

363.6 HP @5200
407.5 torque @4000

Ok, I have what i believe is a holley 650 double pumper, the only id number on it i could find is:

3310-10
0413

Is this a appropriate carb to run on my motor? If not what should I go with?

The engine is going in a 68 el camino.

I also have a old school holley carb which i was told is a better carb than the 650 double pumper. the number on that is:

0690
list-4360-2

I was told this carb needs to be rebuilt but can be jetted a bunch of different ways and would be worth rebuilding.

Any and all info and input is appreciated.

 

[ericnova72]

3310-10 is NOT a 650 Double pumper, it is a 750 vacuum secondary. The only way this carb could have two accelerator pumps on it is if someone threw a bunch of junk together to make it look like a good carb. This would be a good carb for you to use if it is a complete 750 vacuum, no pieces missing.

4360-2 is also NOT a 650 double pumper. I don't recognize that # other than to know that it isn't a regular double pumper #. Does it have 4 equal size throttle blades or are there two different sizes, front and rear? One accelerator pump or two?

 

[454C10]

The 3310 is a good carb (750 cfm, vacuum secondary). should work nicely on your engine if it is in proper condition.

Your biggest power problem is the GM heads. If you need more power then get another set of heads. Should make another 50hp with a good set of heads.

Were did you get your hp/tq numbers from??

 

[pittbull7934]

I can take pictures of the carb, but i dont know how to post them. the 750, looks brand new, and i think it was not installed.

i got the hp and torq numbers from the dyno chart. the motor was dyno-ed on the stand.

the heads have 2.02 intake and 1.60 exhaust.

i was think about adding nos once i get it installed, is that a bad call? it seems like a cheap way to get allot of hp, and the engine is built to handle it.

 

[454C10]

N02 is a nice way to make some extra power. Just make sure you set it up right. A 125 or 150 hp shot will make a big difference.

The valves (2.02/1.60) aren't the problem with the GM heads , it is the port size and flow that is the problem.

That engine should be making at least 400hp. And I feel the heads are holding it back. Unless, it was dyno'd without headers.

 

[pittbull7934]

yea, but new heads are just way too expensive. it seems nos is much more affordable

 

[454C10]

I'll agree with that.

but n20 cost money also. and the kit can be 400 or 500. so, pretty soon you are at the cost of a set of heads. But the power of the no2 is more, however only for very short durations.

 

[pittbull7934]

yea, but even though i would like to take it to the track a couple times a year, i dont think i will use the power provided by bigger port heads in my day to day driving. i think putting the nos on it will be much cheaper but i'll only use it at the track.

I really dont know, but summit has a 125 shot kit for under 400. and i figure a new set of good heads is going to cost well over 1000.

unless you guys can suggest a affordable head swap, i am not swapping the heads.

i am more concerned with whether or not my carb is a good carb to put on my motor (the motor is already built). if i could send one of you guys pictures and you could tell me what you think that would be helpful.

thanks!

 

[pittbull7934]

also, i know this is off topic from the start of this thread, but i was looking at the dyno sheet. and it shows the peek hp at around 363 hp, at 5200 rpms.

my question: Is it normal for a 383 to have such a low redline? It seems that since the motor was built with studs instead of bolts and forged pistons etc, that is would have a higher peak rpm. It seems like i have a very small power band.

 

[ericnova72]

The power peak may be low because the heads are choking it off above this point. If you didn't do any porting to those heads, even with the larger valves the flow will barely be adequate for a 327 cubic inch engine, let alone one that is 55 cubic inches bigger.

Are you sure about the chamber cc of the heads? Compression ratio could be lower than you think. Post the head casting # and exactly what work was done to them if you can.

 

[pittbull7934]

will do, prob post it tonight

 

[pittbull7934]

do you guys have a suggestion of what heads would work best, maybe i can find a pair used.

 

[pittbull7934]

what do you guys think about these heads?

http://cgi.ebay.com/ebaymotors/Chevy-Aluminum-Heads-Strike-Force-2-05-or-2-02-1-6-SBC_W0QQitemZ370211690898QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item5632561992&_trksid=p4506.c0.m245&_trkparms=65%3A12|39%3A1|72%3A1171|240%3A1318

they are affordable for me, but i dont know if they are what i should put on there.

 

[pittbull7934]

The power peak may be low because the heads are choking it off above this point. If you didn't do any porting to those heads, even with the larger valves the flow will barely be adequate for a 327 cubic inch engine, let alone one that is 55 cubic inches bigger.

Are you sure about the chamber cc of the heads? Compression ratio could be lower than you think. Post the head casting # and exactly what work was done to them if you can.

the casting number on the heads is 3973487

all i know is that there was a grind job done on the heads

 

[Deez]

DO NOT BUY THOSE HEADS you will not pick up anything from what you already have I am sure. Spend a few dollars more, and get a whole lot more. You will not be disappointed. The heads you posted up, avg cfm from .100 - .500 is 158. This is far from spectacular. Even if you include the .600 lift numbers the avg is only 174. If you were to look at a regos vortec it would be dang close. A good aftermarket head will put you around or above the 200 avg which translates into more usable power than a lesser flow - never rely on flow numbers alone. Proven heads work while others do not for good reason. Flow is but one of the many. Think long and hard before you go drop coin on something that will disappoint and discourage you. My $.02, take it or leave it. hint: take it and save towards proven performers.

 

[pittbull7934]

DO NOT BUY THOSE HEADS you will not pick up anything from what you already have I am sure. Spend a few dollars more, and get a whole lot more. You will not be disappointed. The heads you posted up, avg cfm from .100 - .500 is 158. This is far from spectacular. Even if you include the .600 lift numbers the avg is only 174. If you were to look at a regos vortec it would be dang close. A good aftermarket head will put you around or above the 200 avg which translates into more usable power than a lesser flow - never rely on flow numbers alone. Proven heads work while others do not for good reason. Flow is but one of the many. Think long and hard before you go drop coin on something that will disappoint and discourage you. My $.02, take it or leave it. hint: take it and save towards proven performers.

ok, i was just turned on to the brodix PN# 1021001 heads. how about them? are they worth the money and where is the best place to pick them up? i would like to buy them with the correct valve, springs etc already in the heads, for my application and my motor. I want to save as much money as possible yet get exactly what i need.

I appreciate the .02$.


I figure If i put new heads on now, i can either sell the heads i have for more then i would if i were to use them, or i could build a 327 or 350 to fit these heads, and put them in another car.

I just need to know which heads to get and who to get them from. ideally i would like to call the people i am getting the heads from, tell them the specs on my motor and have them KNOW what i need in my heads to make the motor perform.

like you said i want to think, and make sure i get the right ones.

thanks again, your feedback is great.

 

[malc]

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