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So, I am pulling my 455 to go LS in my Cutlass. I also have a 56 3100 project truck I was going to drop a SBC/700r4 setup in. How does the 455/TH400 measure out compared to the SBC?
IE, How much trouble would it be to run the olds drive line in the 56 vs the 350 I have?
56 Chassis 350 SBC with baby blower. My Marine built 455.
I’m guessing you will need to fabricate mounts for the 56. No clue if sbc was available for those trucks I’m guessing it won’t be a difficult swap.
Well, as you might be able to tell, the 56 already has an aftermarket setup in it. Cross member setup it has is for SBC. Was a friends project, had a blown SBC in it. He needed money, sold the motor and trans...
Needed more money and finally offered it to me for $$$ I could live with.
And was thinking today, hmm, maybe I could stuff the 455 in the pickup, since I've been wondering what to do with it.
Yes, the Firebird 403 mounts should fit. I still had to add spacers to run them on my 94 Z71 I had with an Olds 350 in place of the awful sbc swirl port.
Last edited by olds 307 and 403; December 2nd, 2020 at 07:02 PM.
Yes, the Firebird 403 mounts should fit. I still had to add spacers to run them on my 94 Z71 I had with an Olds 350 in place of the awful sbc swirl port.
When you remove the Rocket Engine and replace it with a Chebby Motor Don’t forget to remove all the Cutlass and Rocket Emblems and replace them with the Bow-ties, it will no longer be an OLDSMOBILE!
The trans tunnel in those old pickups is really small, so you might have interference issues regardless of which engine. But, check the truck forums. The advice will be the same for anyone swapping in a TH-series auto with any engine.
As mentioned, there are the late 70's engine mount adapters that bolt to the Olds block and offer a mounting location for SBC engine mounts. But since this thing already is completely custom up front, you can fabricate something of your own. And those OE adapters aren't exactly special. I had a set for a while, I think it was really just a piece of 3/8" plate, maybe 8"x1" with a few holes and a couple of bolts stuck in it? Something like that. They are still sought after for folks putting 403's into firebirds, so they pop up from time to time.
My guess is the biggest potential problem is figuring out where the engine sits right now. Since that front is all custom, they may have moved the engine back and down. That's fine for the SBC, but the Olds is a bigger package, so you might have firewall clearance problems. No way to tell until you start mocking things up though.
When you remove the Rocket Engine and replace it with a Chebby Motor Don’t forget to remove all the Cutlass and Rocket Emblems and replace them with the Bow-ties, it will no longer be an OLDSMOBILE!
Well, at least I am staying true to form, upsetting purists. It's all I've done since college.
Put a SBC in a FJ40, then a Buick in a CJ5, 400 SBC in a Model A, 455 in a stock Cutlass, then cut up a stock 58 Thunderbird to install a blown 390/C6 in it., now my newest venture.
Pull the 455 from the Cutlass and go LQ9/4l65e. Probably never would have if some stupid girl hadn't plowed my CTS-V from the rear.
The trans tunnel in those old pickups is really small, so you might have interference issues regardless of which engine. But, check the truck forums. The advice will be the same for anyone swapping in a TH-series auto with any engine.
As mentioned, there are the late 70's engine mount adapters that bolt to the Olds block and offer a mounting location for SBC engine mounts. But since this thing already is completely custom up front, you can fabricate something of your own. And those OE adapters aren't exactly special. I had a set for a while, I think it was really just a piece of 3/8" plate, maybe 8"x1" with a few holes and a couple of bolts stuck in it? Something like that. They are still sought after for folks putting 403's into firebirds, so they pop up from time to time.
My guess is the biggest potential problem is figuring out where the engine sits right now. Since that front is all custom, they may have moved the engine back and down. That's fine for the SBC, but the Olds is a bigger package, so you might have firewall clearance problems. No way to tell until you start mocking things up though.
Interesting, I wasn't worried about the tunnel, figured I was fine there since it already had a TH400 before I picked up the project. I'd assumed I had tons of room there. At one point this is what the truck had installed...
Ah! Should be good if it's already had an auto trans put in it. I didn't know how far the previous owner had gotten.
Also, look what I found! A picture of those magical conversion mounts.
That is half of it, you need the solid mounts that match the Olds V8 block pattern. At least you are putting in the weak 4L65E in your Cutlass, not a great trans.
December 2nd, 2020, 03:57 PM
