a buddy of mine has a 55 olds the previous owner put a 61 394 wit the "slimjim" tranny, the motor has nothing but problems and so thoes the tranny, hes looking to find a newer power train to transplant that would work with the current mounts, any one got any ideas. thanks in advance i did use the search function and all i found was sbc swaps im not saying that he dosent want to use that but he answer by most people is it would be easier to use a BOP engine than a sbc... can some one tell me why
probably the only thing newer that would use the same mounts is not much newer, and will give you the same problems. He probably ought to figure out what exactly he wants, and build it well, and not worry about trying to reuse the mounts.
Most would use the Olds 455 and either a TH400 or 700R4 which would require a motor mount change. While do those improvements, you should also upgrade the front brakes to disc, to handle the new weight and power. Stopping is at least as important as going.
get over onto classicoldsmobile, there is a guy there 'citcapp' that has documented a 455/400 swap into a 56 olds, which is essentially the same as the 55 for motor mounts, but not sure on the auto as probably depends on if it has the jetaway or the dual range hydro. from my limited understanding a 350 olds motor isn't hard to do, as I think some of them came with the same or similar engine mounting. another place would be 'realoldspower' Tony Daytona on here is doing a chev swap at the moment, but I think he has come to a halt of late. I personally think that the 455 would be a great motor to go into a 55 and parts are a lot cheaper than the early rocket motors. But the 350 has heaps of go fast goodies and is as cheap as chips for parts if you look on ebay. not the same visual appeal as the early rockets or even the 455 though. the other option would be to look for a better/rebuilt early rocket motor and box.
If the slim-jim is the problem, dump it and go back to a slant pan or dual-coupling Hydramatic. I think you can use the iron bell the Slim Jim uses to adapt to the Olds block to run the 56-up dual-coupling, which would let you get one from any 56-60 Pontiac, 61-64 Bonneville, 56-64 Caddy, or 56-60 Olds. I'd have to think you could go to a slant-pan with it, too, but you might need to get one complete from the block back. For that matter, I wouldn't be surprised if there's an adapter to connect the 394 to the later transmissions and you could put a 200R4 or 700R4 in there.
i think his biggest issue is the money factor to re build the 394, i dont want to pull the sbc card but anothe buddy of our has a chevy 400 running motor who is willing to give it up for free, as far as the slimjim he told me that the adaptors for a newer trans are arround 1000
No offence, but the project sounds doomed because he must be way inexperienced in building/modding stuff, if he is trying to "bolt a late model in the stock Olds mounts". So, we know the mounts need a complete redo for starters, then how about ALL the rest of a swap??? Driveshaft mods or new one, trans linkages, throttle stuff, cooling issues with a 400 sbc, Radiator mods? Exhaust mods or new stuff, The list goes on, and it all stems from the thought that a "free" motor is a better option than an early olds. Doomed progect IMO, due to lack of skills/money
I had a 55 Olds 2 door hardtop that I literally snatched from the claw at the local recycler for $125. OK, it was awhile back, but the low mileage Olds 394 and slim I had in it kicked tail on a regular basis. I bought a 61 four door sedan that had been rolled because it was still running the original valve stems 20 years later with only 50K on it and the little old lady popped one off on a turn. Brakes and all went over sweet into the 55 and worked great. Good luck with yours however you decide to finish it...........
I meant no offence. It is only because the guy wanted a motor to drop into the olds mounts. That is a sure sign that this is a very inexperienced person as far as a major swap. Sometimes the truth is hard to hear. He isn't the only one; a 55/56 olds owner posted the same exact wish list on Hamb within the last year. and most guys warned him that he'd likely end up with a barely started project just sitting there, because he did not realize what is really involved. Don't forget....YOU asked for advice
thrust me i didnt take it the wrong way, i read the other threads and i know where it might have gone he is inexperience in fabbing work, all he wants is to be able to cruise and not have to worry that hes not going to make it back home
If you want to rebuild the 394 and use a slant pan dual range hydramatic, you will need to take the crank and have a pilot bushing installed. Then you will need to get the hydramatic flywheel counterbalanced to the crankshaft. After that little things like driveshaft length will need to be addressed. You may also be able to use a dual coupling hydro from a Pontiac or Olds, but the Cadillac has too long a bell housing to mate to the Olds. The Pontiac and Olds use a short bell housing and should work.
Willys: I can tell you know what you are talking about as I had to contend with the tailshaft length when dealing with a later drivetrain swap and encountering the X member. Nearly impossible to make race tuned headers work either. But, it depends on how far you are willing to go. Right?
Yep, just about anything is possible. My only advice is to rid yourself of the Slimjim, it is bad news. The 394 is really a good engine, but rebuilding it will run some dough. Same for hydros, but it will be a strong runner.
I didn't care to see another abandoned project when a "free" motor and trans starts to turn expensive. Just adding up some very basic items like: new rubber mounts for the SBC, or late BOP swap, a basic metal motor mount fab kit, Headers? which ones to order? will they clear? will I have to ship them back?, a used or new donor radiator, New hoses, belts, thermostat, water pump while you are there...oil, filter, trans oil & filter...etc etc. Sometimes we let ourselves forget the big picture. I did not say don't do the late motor and did not say don't rebuild the 394. If you choose the SBC, yes there are people here who have done it on the cheap because they have a decent amount of fab skills, welders, cutting tools, a good place to work, and places to get cheap donor pieces. So it can be done.
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