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Old 06-15-2006, 06:18 PM
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72 Nova, 65 Rambler, 37 Chevy
 
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1972 Nova I6 to V8 Engine swap, what needs to be done?

This is a long one....so hang in their, please help me out! hehe

Im sure this has been done a million times over and I think I have everything down....I have a 1972 nova with a 250 and powerglide and I will be swapping in the 350/350 combo (ofcourse) within the next 2 weeks. I believe that motor mounts, throttle linkage, are different as far as engine bay stuff goes...ofcourse Ill need accessory brackets, and different exhaust system, which I already have....

1. But Im confused on my kickdown cable or is it called a detent cable? The one I have for the Th350 has been cut, I may be able to congle up somthing and make it work, but does my powerglide have a cable I can use? I took a quick look and it looks like kickdown is done by a lever type linkage. I asked if checker auto has one and they have one but its called a detent cable(same thing right?) but they said I need to find a number off it or something??? Which I don't think their is one. Can someone help me here.

2. Also I read that 1970 up nova's use a cable for throttle...Which 6 cylinder and V8 is the same...so I can use my original throttle cable? (its a Rochester 1bbl now...will be a Rochester Q-jet.

3. I also will be using a HEI...I heard that I will need to dent firewall for clearance, yet others say it will fit?

4. I also found out that I6 and V8 radiators were both the same...unless the V8 had air...which it has a larger radiator...So Ill use my original radiator too, But I think Ill need a fan shroud? Anyone know where i can find one for cheap?

5. And the PG and Th350 are a direct swap, right up to cooler lines and driveshaft and all the way up to my column shifter. (ofcourse different indicator but I think Ill just use feel for now untill i can find one) Update: I just read that their are kits to convert the shift selector to three speed operation, now Im confused.

6. What about headers clearing my steering box? I have flowtech ceramic coated afterburners.

7. And what about this alternator thing I have heard about. On the 250..its on the driver side, but for a V8 its on passenger...so it has to be rewired or something?

8. But wait theirs more...the 5/16 fuel line for six....is that gonna be enough to feed a 350(224* .465" cam, weiand action+, q-jet, headers, 1.94 882 heads)

Well fewf thats all I can think off, Thanks all for your help

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Old 06-15-2006, 08:38 PM
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1. Kickdown cable = detent cable.

2. An accelerator cable for a '72 Nova with 4-bbl is dang near impossible to find, and in fact if you find a source, let me know, because I need a spare. The problem is that the front end of the cable attaches to the carb with a ball-and-socket joint. There's a ball on the carb lever, and a socket on the cable that pushed onto the ball with a springy clip to hold it. The 6-cylinder and 2-bbl V-8 cables are not the same as a 4-bbl cable, and there weren't that many 4-bbl Novas made, so the aftermarket doesn't seem to want to tool up just to sell you and me and 6 other folks a cable. BUT, if your carb has a regular pin-with-a-groove-in-it stud for a cable to hook to, you might try a cable from a later-model Nova. Later in the '70s ('77, for sure), they used a cable with a flat end with a hole in it for 4-bbl Novas, and you can get them from Motormite. I don't know if the pedal end or the floor attachment is the same, but it might be worth a try.

3. Some cars need the firewall "customized", and some don't, for some reason.

4. Fan shroud is another hard-to-find item, although there may be an aftermarket one by now. Check vendors at www.stevesnovasite.com . A/C cars came with an air deflector that mounted underneath the radiator & bumper area to force more air through the condenser/radiator. Also a can't-buy-one-new item, but not too hard to fabricate if you need one.

5. A T-350 column shouldn't be too hard to locate. Shiftworks may have a conversion quadrant.

6. Header clearance is the same old crap-shoot. Might fit, might not.

7. You might need to make the wires longer so they'll reach.

8. I can't say if the fuel line is adequate, because mine came with 3/8". I suspect it'd be OK, but maybe somebody else knows for sure.
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Old 06-15-2006, 09:33 PM
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i did the same thing you are doing so I may be of some help.
1. I had a th350 already so I dont know if your cable will work or not but they are cheap and easy to switch out.
2. ate first I used a coat hanger ( dont do this its not safe) intill I got a cable from a 78 camaro at the yard.
3. I use to have a 74 nova with the hei and it was a pain in the butt to take that cap off. so on my 69 i found a pints type and used a petronix inside.
4. I bought an aluminum radiator from jegs for 180. dont get anything bigger then 26" or you will have to relocate your battery.
5. I test drova a nova I was going to buy and it had the pg column but it was a th350 so im not sure if he changed anything or it just bolted up.
6.I have hooker caoted headers on mine and they were a pain to get in and barely tap my box on revs. not much just enough to scratch it. also dont put your dipstick in till you mount your headers. I snapped mine off and now I only use those braided steel flex hoses.
7.I didnt rewire my alternator I ran it over my intake and it fit perfect. I was worried at first too then I decided to just try it.
8. the fuel line is enough for a v8. I also have the 5/16 line but I vae a 3/8 line from the hard line to the pump then to the carrb. I recently changed my sender to the 3/8 style so all i have left is that hardline form the tank to the pump.
let me now if you need anthing else i wish I had someone who did that before so i knew waht i was up against but i didnt. one more thing you might have to hammer this little knub on your subframe were your frame mount will bolt up. It wasnt hard it was just unexpected. and be sure to get the mounts for the year you get your frame mounts from they changed quite a bit over the years. Im using some from a 67 camaro I got on ebay for $10.
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Old 06-16-2006, 03:52 AM
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The column from the powerglide will work with the TH-350, the detents are in the trans not in the column. If you hooked it up as is the indicator on the dash will match for P,R,N after that it will not read correctly, but 1st, 2nd and 3rd will be there. The conversion kit you mention most likely is a new gear indicator lens.
I have changed a couple of 68 to 72 Nova's from 6 cyl PG's to V8 TH-400's and used the original column. It has been 20 years +/-

When I did my conversions the throttle cable was still availabe from the dealer, not likely to be the case now.
A quick Google search turned up this, throttle cable http://www.yearone.com/serverfiles/f...ain2.asp?cat=6
I checked the link, it does not take you to the listing, on the left click on air/fuel, then under carburators, accelerator cables and bracket.

Last edited by 1ownerT; 06-16-2006 at 04:05 AM.
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Old 06-18-2006, 09:32 PM
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1ownerT, thanks for the cable info.

Warrant, if you have not bought your mounts/brackets yet, try to find some for a '72 350. That one used the mount with the built-in interlock that keeps the engine from jumping around if the mount fails. A broken left-side mount with no other means of restraining the engine will cause the throttle to open up unexpectedly on left turns. This may sound like fun, but it's not.
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Old 07-05-2006, 10:44 PM
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I have points distributer now....Ill be using the HEI, Dont I need a different wire or somthing to supply a full 12 volts to the HEI?
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Old 07-06-2006, 07:46 PM
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You need a full 12volts to the HEI. The points setup is fed by a resistance wire that cuts the voltage to the coil. Here's an article on converting a Pontiac, but the basic idea is just the same.

http://www.boyleworks.com/ta400/psp/HEIconversion.html

GM part no. 8917052 (~$4) is a pigtail with the distributor connector.
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Old 07-20-2006, 11:02 PM
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Im damn close from installing my engine and trans. My plan is to drop the engine in with pretty much everything already installed, all pulleys, dizzy, power steering pump, fuel pump, alt. etc, with the trans bolted on ready to go too. Engine would be pre lubed outside, and ignition timing all set up then just drop it in and hook everything up and break in the sucker.

Does anyone know if everything will clear if I install like this? (minus headers and fan and stuff like that and ofcourse the radiator will be out)

Thanks

Last edited by Warrant; 07-22-2006 at 02:48 PM.
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Old 07-22-2006, 02:49 PM
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Any of you nova guys know my question to post 8?
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Old 07-23-2006, 08:44 AM
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I have done the swap a few times, but like I stated in an earlier post it has been 20+ years since my last one. To be honest I do not know for sure, I don't think I ever installed one completly assembled. I always dropped the engine in then the trans, maybe I liked to do things the hard way??????
It would probably go, although I would be very carefull with the dist. installed. You will need to be at a pretty good angle with the assembly to get it started down in, a good engine leveler is a must. The car will need to be on jack stands.
I would set the headers in as the engine is going into posistion, they can be a PITA one the engine is in place and you have to install from the bottom side.
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Old 07-24-2006, 01:14 AM
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I'd leave the distributor out, or at least leave the cap and rotor off. There's very little room between the cap and the firewall even with a small-body distributor, and with the nose of the engine tilted up, the distributor cap is tilted back, right into the firewall. The firewall wins every time. The fuel pump can also be a PITA, especially if it has tubes sticking out.
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Old 07-14-2007, 09:26 PM
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I6 to V8 conversion in a 73 Olds Omega (nova)

I was reading some of the comments in an earlier discussion and had a problem with a similiar car....My son (16 yr old) is changing to a 350 chevy small block. We have just installed the block using the frame mounts from the 250ci six that was in it. The oil pan actually touches the frame crossmember and the harmonic balancer is just touching the steering linkage. Is there a taller mount available or anything suggested to raise this up just an inch? Would washers/spacers under the mounts work? Also, will the six cylinder power steering pump work on V8?
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Old 07-14-2007, 09:44 PM
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First off I`ll mention you should have started a new post, as this one is over a year old. Second, the ears that mount on the engine of the small block chevy come in a few different heights. I learned this playing around with them. When I dropped a small block in my cutlass I didn`t like how high the fan was up even so it cleared the shroud, and the front end would not settle back down to it`s normal height. Later when I did the next engine swap I compared the ears I had to the ones that were on a chevy pick up, I noticed the ears off the pickup were much lower, So I used them on the new engine and it sat in there like I wanted it to, nice and low, the front end finally settled down to normal height, and the fan was in the center of the radiator like it`s supposed to be. Find some different mounting ears and compare them, when you find the taller ones you`ve found the ones that will correct the problem. However this only works on the newer style mounts, not the mounts these cars originally used in those model years. When most do this swap they use the newer type mounts, as the older ones had bad habits of breaking, even when used with a low powered engine. If you used the old style original mounts, then I`d switch it over to the newer style, But I`m thinking you used the newer style, had if you used the original, everything likely would have cleared.
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Old 07-14-2007, 11:20 PM
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I'd use 73 style motor mounts and avoid the hassle of those older tear apart style mounts, the subframes were the same from 68-74 so they will interchange just fine. HEI clearance is tight and usually requires some firewall massaging for good clearance. The steering column will work just fine. 5/16" fuel line will easily support 350hp, The throttle cable should be an easy find off a donor vehicle-I think I used one off of a truck or Monte Carlo in the past. Or you could go with the 68-70 style mechanical lever-it will bolt right in on your firewall the attachment point is there at the gas pedal pivot. Driveshaft is the same. You'll need to install the drivers side header from the bottom and the passenger side will usually slide in from the top-remove your dipstick and sparkplugs first. Replace the resistor wire feeding the stock coil from the wiring harness and bulkhead and replace it with a good 12 or 10 guage wire to feed the HEI-no need for a relay because the rest of the ignition circuit uses good sized wire. You can lengthen your alternator wiring so it goes along the firewall and out along the right valvecover to your right side mounted alternator-makes the wiring a lot cleaner looking. Take your time and do things right.
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Old 07-15-2007, 11:01 AM
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if you have to buy a distributor go with the smaller dist. cap and ign. setup. That will eliminate the guess work. I have a 72 nova also and cut the firewall, made a box, to clear the distributor, and smoothed everything. get a universal kick down cable and the right bracket and you'll have no problems. the left turn deal is real. the car can take off when a mount is broke i have done it with a car in front of me pulling into my high school parking lot of my senior year. Fortunatly i shut the car off before i hit the other car. hei may fit but its so tight.
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