Just purchased a CLEAN 1985 Fleetwood coupe RWD with a blown engine. My question: Can I use the engine and possibly the tranny from a 1997 Chevy 1500 P/U, 8 cylinder. Will this job be a simple pull and dump or will there be some modifications.....I know this topic has pretty much been beaten to death but I don't want to be another HT4100 victim.....Also, do i have to swap out the computer.....Thanks for the advice....Can't wait to get this classic on the road with the full 90 package...

Is it the 305 or 350 V8??? It doesn't really matter, just wondering.

You will need to use the new computer and will probably need a custom wiring harness. Probably have to fab up some new motor mounts too, and remember the trans is different. The stock one is a 200R4, while your new one is a 4l60e. The 200R4 will not last with all the new power you'll be putting down. Probably will have to fab up a bunch of new vacume lines, and hopefully the power steering pump with that engine will work. Might need a new fuel pump as well, look at what sort of PSI the stock one puts out and see what the one from that Chevy truck puts out.

Talk to the folks at speartech. www.speartech.com They can custom fab a wiring harness for your application.

Swapping in a fuel injected motor is never an easy feat. The wiring is always the biggest part of the project.

^ Amen.

If you can't do that, go for an Olds 307/350 (350 is preferred because of the weight of the car). They're simpler to work on from everything I've read, and bolt right in.

sting, your forgeting something...
as my sons friend Dora says: say click, take a....

don't go with the 307 olds, easy to work on but it has no power when put in a big car like these Cadillacs.

Sounds like alot of work Aron...I may take Stingroos advice and go with the 350 olds.....Thanks guys...all the best....cant wait to show you guys the finish product....

By all means, not my advice. lol I just live here. I'm nowhere near as tech savvy as half the regular posters here, I just read a lot.

I respect your opinion and my search for a olds 350 will begin....

I put the Olds 350 in my 90 and it was pretty easy but I dont know how easy it would be to swap with a 41 cause I dont know much about it. To my understanding, its a carbed motor very simular to the 307? Now if I could get the brakes fixed I'd be able to tell you how it drives. We did put a 307 vin 9 in the 87 and thats a big improvement. Well worth it if you get it cheap enough. burnouts, doughnuts and all.

If you have the chev pick-up already and want to use the power train, it will fit.. They used 305-350's in the 91-92 FWB...so these can be bolted with stock parts, like motor mounts and exhaust... the hardest part is changing the wiring and computer..
If you could find a good running 77-79 caddy with a 425.... that would be the way to go.... the donor car would have all the parts to do the job... BUt if you don't change the tansmission and rear end [you don't have to] save them.... because you will need them later.. those 200 4R's are weak in stock from, so's that 7 1/2" rear end... the TH400 and the 8 3/4" rear are strong..

I put the Olds 350 in my 90 and it was pretty easy but I dont know how easy it would be to swap with a 41 cause I dont know much about it. To my understanding, its a carbed motor very simular to the 307? Now if I could get the brakes fixed I'd be able to tell you how it drives. We did put a 307 vin 9 in the 87 and thats a big improvement. Well worth it if you get it cheap enough. burnouts, doughnuts and all.

The HT4100 had a different block than the 307. It doesn't share any of the internals either. It was fuel-injected (TBI) and the 307 was carbed. The TBI was the only redeeming feature. ANY Olds engine is better than the HT in my opinion. That's why I'm building one.

The 307, 350, and the 403 Olds engines are direct bolt-ins. The optional engine for all HT4100 cars was the Olds 350 Diesel. The 307, 350, 403, and the 350 Diesel share the same engine block, so they drop right in. The mounting holes already exist in the car. It will also bolt to the trans, since the 2004-r has the dual BOP/Chevy bolt pattern. Good luck, they are great engines!

The HT4100 had a different block than the 307. It doesn't share any of the internals either. It was fuel-injected (TBI) and the 307 was carbed. The TBI was the only redeeming feature. ANY Olds engine is better than the HT in my opinion. That's why I'm building one.

The 307, 350, and the 403 Olds engines are direct bolt-ins. The optional engine for all HT4100 cars was the Olds 350 Diesel. The 307, 350, 403, and the 350 Diesel share the same engine block, so they drop right in. The mounting holes already exist in the car. It will also bolt to the trans, since the 2004-r has the dual BOP/Chevy bolt pattern. Good luck, they are great engines!

I see, but it seems alot of people opt to put the carbed Olds 307/350 in where the TBI 4100 used to be. Is there a particular reason for this? It would seem that a TBI sbc would be easier with wiring and all.

From what I have been able to gather, the Chevy engine would need custom engine mounts. The Olds engines bolt in because of the option for the Olds engine. As far as the TBI goes, you would need a different throttle body, and a different computer, and find some way to wire it all together. With the carbed Olds engines, there are only one or two wires to mess with, and no custom fabrication is needed.

WOW...you guys are a wealth of information....the 77-79 caddy engine advice sounds good...looking for a simple project...no real crazy fabrications...Im just afraid of the fuel injection to carb conversion...not really too confident about the wiring....the pull and dump should be easy....

If you do go to a larger motor I would highly recommend beefing up the rear end as well. The HT4100 powered cars had a weak rear end.

From what I have been able to gather, the Chevy engine would need custom engine mounts. The Olds engines bolt in because of the option for the Olds engine. As far as the TBI goes, you would need a different throttle body, and a different computer, and find some way to wire it all together. With the carbed Olds engines, there are only one or two wires to mess with, and no custom fabrication is needed.

My '82 Deville didn't have the bolt holes for the engine mounts for my Olds 307 I swapped in to replace the HT4100. I had to drill them myself. Also had to move the cross member back and drill some more holes to bolt it up further back. I sat and researched engine / trans mounts for my car for so long trying to get something that just bolted in. It's actually really easy, quick, and painless just to drill out what you need using the stock mounts for the engine / trans.

The HT4100 mounts look more like chevy mounts than Olds mounts.

I don't know if there was an Olds engine option in '82 and this might be why the predrilled holes weren't there. :confused: