Hello All,
I am the new owner of a 88 cutlass supreme classic. It currently has a 307 in it, I have a 455 that I would like to put in after completing the build. I was wandering has anybody done this and how difficult will this task be for me. I got the motor and transmission out of a 76 delta 88. Will this work or am I dreaming?
depends on the motor specs. is it stock or do you have work done?
with the extra torque your def going to want to change your weak 7.5 rear to an 8.5 or at least beef up the 7.5 (axles/posi ultimately more spline and preferably welded axle tubes, s10 wheel cylinders ) to handle some abuse. also expect some money to disappear when getting headers- you dont have a big selection to choose from and they arent cheap. also if you have a stock 200r4 trans in that thing ( as opposed to a th350 i believe ) while everything is out and apart might as well find a th400 which uses the same x member or beef up the 200r4. those are the main concerns i would advise you of for starters. its not a 1-2-3 pull out drop in job.. but its worth it when your done. just expect to spend some $
transmission beef up for 200r4 $600
headers $500
8.5 rear or rebuild a 7.5 $700-900
your over 2 grand right off the bat. if you have someone else do the work
You're gonna love this swap when it's done, and it's really not difficult.
The 455 drops right in with no modification.
One thing to consider is that your trans is out of a full-size, and probably has a medium or long tail shaft, making it not the best choice for a G-body.
A built 200-4R is the best choice, but they're pricey. If that's out of your range, then get your hands on a short tail TH400.
You'll have to have about 1/2 - 3/4 of an inch taken out of the driveshaft.
Another thing you have to decide what you want to do on is the exhaust, whether you want to run headers or manifolds.
Repops of the factory high-performance manifolds are available for around $400, the cheap headers are about $450, and the fancy headers are about $750.
On the street your 7.5 rear will probably be fine, but with sticky tires and hard launches it's days will be numbered.
When shopping for an 8.5 sometimes they also have the driveshaft and 200-4r from the GN/Ttype/442 that it came from. Getting the drive shaft with the rear makes it a bolt in. As far as building up the 200-4R check out www.extremeautomatics.com.
www.robertpowersmotorsports.com Bob did a street built Olds 455, 800 Q-jet, 200-4R, lock up converter combo and has good info & pics on his site. I believe he ran a 12.3 at 110 mph in the quarter and got over 15 mpg still dialing it in before it was stolen. Another guy Dwight I believe with a gray Cutlass that posts on www.oldspower.com has a street build Olds 455, 800 Q-jet, overdrive with lock up converter that runs 12.0s at 111mph & gotten close to 20mpg. I used a mild Cadillac 500, 800 Q-jet, built 200-4R & lock up converter in the 442 in my pics. It ran 12.5 at 110 mph & got 17mpg hwy. Naturally if you are hot rodding it around town you can get it to drink to the tune of 10 mpg. (About like you would get from the typical 3 speed & a Holley combo.) Warning the instant push you in the seat of a long stroke big block is addictive. You can spin, gear, & converter a small block into being fast but nothing is more fun & enjoyable then a well set up big block.
Thank you all very much this helps alot. I was going to have someone build the transmission that I have but now I beleive I will find the th400. I was hoping that I would not have to do anything with the motor mounts so that helps. Thank you all again.
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