Hello guys...
I didn’t know where to put this, but figured that I could get some help in here..
I recently got this '91 caprice classic that's like brand spanking new with 25.000 miles on it, it has the 5.0 TBI engine and it's auto (what else huh)...

I have a 383 LT1 engine in my garage ('97 model) that went 11.60 at 120 in my old 3700lbs WS6.. Yep that's right!!
It's a complete motor with the OBD2 PCM and new mcloed street twin clutch (correct tune with CATS program but for T56 car).... but that's it, I don't have the 96-97 Harness for the motor, but since I' am doing a swap, I would be better off to get a custom harness, right?

ANY input would be great... I' am thinking (not certain) of using the 700 transmission (is it manually shifted?.. I mean not computerized shift points and such.. (than the T56 PCM should work, correct?) sorry haven't looked).

What's the easiest and best way to do this? I' am not much of a electronic wizard but doing the hardcore install work is no problem for me... I work as a machinist and can do any fabrication/welding and such if needed.

Where should I look and who should I contact??

I realize the diffrent fuel system, swap the manual fan to electiral, trans mounts and such..

Can you say sleeper?… bwahaha

Thanks.
KR

 

Going to have to notch the crossmember for the AC, would even have to do that with a b-body accessory bracket as the crossmember changed a little for 94 when they put the LT1 in.

PCM will need some slight retuning almost no matter what you do, at the very least even if you use the T56 the speedo would need recalibration.

Depending on your streetability wishes for the car you might consider getting a 4L60E, the tuneability is fantastic. The 700R4 will work at least for awhile, going to have to address the lockup of the TC though as that is computer controlled. These trannies CAN be built for the power you have but only a relative few shops are capable. A lot of shop claim to be but are not. Get a good converter to put in front of the auto, Edge, Yank, Vigilante 9.5".

The big b-body forum is down for maintenance but once it is back up wander over there and you might just be shocked to find out what guys are doing with these whales.

The skirted rear wheelwells on a 91 are going to be a PITA to get rear rubber inside, the 93-96 cars with the open rears accept a lot of tire with ease. I am running 27x11.50 Hoosiers and have run 28x10.50 ET drags, guys who move the axle back a little run even more rubber.

 

Thanks for the info.....
Will dive into that forum when it gets open again.. Maaan I love the suspension on this car compared to the 3 link on the F-body, it's the same as my 69 GTO...LOL
But yes they are spermwhales that's for sure.
I might just look into the T56 deal..

 

I think someone in Mass. is making a pedal kit. There was a company that made whole T56 swap kits but they closed up maybe a year ago.

Take a look under the car it could have either a 7.5" or an 8.5", if you have the 7.5" you NEED to get an 8.5" and matching driveshaft(oem or aftermarket), think of all the axle problems f-bodies have with power then imagine adding more weight. The 7.5" was found is base engine civilain Caprices with things like tow package, 9C1(cop package) or big engine options causing it to get upgraded to the 8.5" which is pretty solid. Some guys launching on slicks with a T56 hurt it but that is about it and even then it is usually the heavier cars like wagons.

Going to want to consider decent LCAs for it, wheelhop will be a problem with the stockers, look at UMI.

 

Talk to these guys: http://www.painlessperformance.com/index.php

They can make you the harness you need.

 

Sent the tech guys at Painless an email.... see what they come up with.
I'll be having the car up on two post lift in the week to inspect things.. can't see **** this thing sits so low.. hehe
Have you seen any bench cars with T56, it would be nice to fabricate a long hurst shifter coming out of the floor... here I go again day dreaming
I bought a 12 bolt mooser in my old firebird because I broke my 7.5 with street radials on the street... what a carnage LOL

Where is that Big body forum...

Thanks for the tips!!

 

At least on these the 8.5" is really easy to find and a direct boltin, the '89 and later variety being 30 spline is as strong as a 12 bolt. Guys have done 1.4 short times on stock axle shafts reliably.

If you are in Wisconsin I might even be able to help you out on the axle and such.

http://impalassforum.com/noncgi/ultimatebb.php

 

Yes good news.. 8.5 big rear and limited slip diff. woohoo but the gear ratio is around flat 3 I belive... I'am going for 4.10 gears, no doubt!

 

If counting driveshaft revolutions came up with 3.0 then it could be either 2.93 or 3.08. If you want to keep ABS with 4.10s then a custom reluctor is in order and I can point you the right way. GM made reluctors for 3.42 which was an option 93 and earlier, and they actually made a 3.73 reluctor which is dirt cheap.

Really for a street car with an automatic and a good stall 3.73s are nice, I have managed some low 1.6s with 3.73s and 3400 stall with little suspension work, aiming lower though. With a T56 though 4.10s or even 4.56 are better because of the high OD. The steel shaft wont like it at high speeds though, way too long too spin a steel shaft that small in diameter, critical speed becomes an issue.