Thread: Engine Swap

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I have an 85 Cutlass Supreme V6. Can anyone answer a question for me. Id like to put a V8(327 or 350) if possible. Anyone have an opinion on which would be better and how hard of a swap would it be? thanks alot for your help

biggdadiek, I had a early- mid 80 cutlass with a v-6 that I put a v-8 into, I kept the v6 tranny in and redrilled the bellhousing holes to match with the v8, NOT RECOMMENDED, it lasted 8 months, But both were junkyard cars so didn't matter.
The V-8 cam out of a stationwagon, can't remember what. but I think it was a malibu.
This swap wasn't too hard, but you just gotta think is it worth it to do this?
for me at the time it was, because I was told you couldn't do it without an adapter, the only reason it lasted only 8 months was that it was involved in an accident with the rear end of a semi, and that bent the frame enough to cause a problem with the torque converter which finally gave out 6 weeks after the accident. and this was with the car being driven 80 miles a day, 7 days a week for the 8 months.

As far as the swap goes, if your Cutlass is the rear wheel drive Monte Carlo clone, you will need V8 motor mounts and to relocate the frame mounts. You will likely also find you need the bigger V8 radiator. If it's the 229 Chevy based V6, a small block will bolt to the original trans, but if it's the 231 Buick version you'll need to trade out transmissions.

I've seen more than a couple of posts lately about 283/327 chevy small blocks, and on another forum about 289 Ford SBs vs their newer counterparts (350s and 302 Chevys and Fords respecitvely (sorry streets were not talking about 302 Z28 engines). ) ).

For their time these were very good engines and in certain factory configurations made very impressive HP to CI numbers. Modified correctly and in the right cars these engines were the terrors of their day. Even today when us old farts get together and stories are told about them they just seem to get faster and faster (in direct ratio to the number of barley pops we drink).

Just my opinion, but I'm afraid I'd have to say the day of these engines has passed just as it did for the flathead. That is not to say that they arn't good engines, but if originality isn't a factor, they are not what I'd generally recommend for an engine swap. I have several reasons for saying that.

1. Real horse power numbers. Generally when we bench race about these old engines we're talking about the factory hi-performance versions or ones that were heavily modified. In reality the majority of these engines were the low HP versions that need to be extensively modified to make the good numbers.

2. To get the good HP numbers the factory generally used extreme compression ratios (by todays standards) in the 10.5 and up area and 11:1 and even 12:1 was not unheard of. This was also usually used in conjunction with a radical solid lifter cam, better heads, intake, and exhaust than found on the more common low preformance engine your likely to come across.

3. Cost and availability. The supply of these older engines is drying up and the engines I've seen seem to fall into 1 of 2 catagories overpriced or free. In the case of the free ones, you generally get what you pay for. In most cases, the engines are generally worn out and will need to be completly rebuilt prior to being placed into service. There is also the problem of identifying what you are getting, you'd be amazed at how many "Corvette" 283 or 327s that I've had customers bring in over the years that turned out to be low HP 2BBL engines and in one case a 307.

4. Actual cost of rebuilding these engines. As these engines are no longer as popular as they once were, the parts to rebuild them have been going up for the last several years, to the point where they are not the cheapest thing to rebuild (definatly more expensive than the 350s and 302s). Additionally, when the heads are rebuilt besides the standard valve job and guides, the additional expence of harded exhaust seats (or latter model heads) should be added.

5. In the case of the SB Chevy the 68 and earlier heads did not have bolt holes in the end of the heads and require the earlier accessory brackets that are becoming difficult (expensive) to find.

I'm not saying that the 283/327/289s arn't good engines, just that 350 and 302 are GENERALLY a smarter choice.


TRUE STORY: Last Fri I took the wife's 302 powered Cobra II into town to talk to a friend. While we were BSing, a 20 something kid came along and was admiring the car. His comment when I told him it was a 302 was that I should "put in either a 289 or a 5 liter to make it go faster".

Having put a 305 then a 350 in an 82 malibu (to replace chevy v6), same basic car as yours.

Rad should work - we never had a problem, and ran AC too.

STRONGLY MOST DEFINITLEY recomend front V8 springs - we tore the y-pipe off more than once, and speed bumps would beat the car up BAD.

we used the motor mounts from our donor car - 78 camaro, so these should be pretty common/cheap to get.

to use a chevy engine you'll need a chevy trans, teh BOP (buick/olds/pontiac) engiens use a different bolt pattern If you want to keep your tans, you could try a 307 olds, 301 or 350 pontiac motor

alright thanks alot for ur help guys

I have a eldebrock scorpion intake man. Would like some data if anybody could help i,d apriciate it thanks

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2434113403

$75 if you get it here...from Estelle!

Looks like a small block verison of a Tarantula i had on a Dodge 400. Single plane, aluminum, looks like air gap, short stright runners...top end type of manifold.

for the small block swap to the cutlass, shouldnt be a problem, i just swapped in a 350 to my v6 malibu which uses the same frame crossmember up front. i also helped a buddy swap one into his 84 cutlass. get original motor mounts for a malibu or monte with a 350 or 305. when bolting the mounts to the frame all the holes are there and the mounts go to the front of the crossmember. the bottom hole will hang off the front of the crossmember and you will only be able to use three bolts (this is better anyway, the bolts are a bugger to get in.) all 4 holes would line-up if you move it back 1" but the engine will be too far back. i know from experience, we had to take it back out and remount the motor mounts. i was lucky enough to already have a th 350 in my car but you should be able to swap one in and the driveshaft may still be the same length, if not it shouldn't be a hard find at a salvage yard. i also had no problems using my existing radiator.