Newbie here. I have a 84 cutlass that had a sbc 350/th350 when I bought it. Spun a rod bearing so I pulled the engine. Have access to olds 455/th400, so I'm going to make the swap. I used the search function to try and find a list of what will be needed. Didn't find much, but I thought I read that 307 motor mounts would work. Also, stock manifolds must be used, unless I spend a bunch on special headers. Am I on the right track? Any suggestions are appreciated. I do have the 7.5 rear, and I know that will have to go. Thanks, Ryan
84 cutlass sbc 350 to olds 455 swap
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It depends on what the car originally came with for an engine. It also depends on how much of a hack job the previous owner did to put a Chevy into an Olds. So far all I can really tell you is that you will need the motor mounts and the clamshells that came from a 307 Olds Gbody.
She is going to be fun now! Sorry I don't know the answers but can point you in some good directions in addition to what you should get here. www.oldspower.com and www.robertpowersmotorsports.com. Kooks makes a quality header for this. I remember reading something about useing the clamshell part of the 307 mount as its lower. Someone will kick in or it might be on Bob's site that I linked. Also I think you can use a WZ manifold which has no crossover and allows true duals with much better flow. I belive they are available as an approved aftermarket also. Crap maybe thats the Pontiac not sure. If you keep regular radials on it you can get by with the 7.5 especially with a support cover. www.taperformance.com. Look under products, support covers, they manufacture them then sell them direct and to dealers who resell them.
Vern said:
307s don't use "clamshell" mounts. There are metal brackets that bolt to the frame and rubber mounts that bolt to the engine. The metal frame brackets are the same on the 78-88 A/G body cars and the 77-90 B-body cars, so any of those are appropriate donors. The rubber mounts are readily available from any auto parts store. I just bought a pair for my Custom Cruiser from Advance Auto Parts for $8 each.
The TH400 should be a bolt-in since it uses the same crossmember location as the 200-4R that was stock in your Cutlass. The driveshaft will need to be shortened and you'll need the correct front yoke.
Since you don't have any 307 accessory brackets, you'll need to get appropriate Olds brackets. The 307 brackets are more common but require small modifications to fit the tall-deck 455. If you plan to use the original R4-style A/C compressor, you'll need to use the modified 307 brackets. If you don't plan to use A/C, just get the 68-76 Olds brackets, which fit both big and small blocks. Olds used three different water pump lengths, depending on whether you had A/C or not. Get the pump, brackets, and pulleys as a matched set.
Kooks headers are great but pricey. The 69-72 W/Z manifolds will also work.
Good luck.
What direction are you hoping to go with the car? Street? Strip? Both?
The short shaft TH400 and the 200-4R are the same length, and you will only need to change the slip yoke. If it's a long tail shaft, then you will need to have the driveshaft shortened.
Reproduction W-Z manifolds are available, and would be a good way to keep it simple as well as keep underhood temps down. Headers give off a lot of heat into the engine compartment. If you go with headers, Hooker and Kooks are both good choices. Do Kooks wrap around the frame like the Hookers do? You'll need to make some sort of steering stop to keep the front tires from rubbing on the rear primary tube that wraps around the frame rail. Anyways, make sure to buy them painted, not pre-coated. Fit them, pound as necessary, then have them coated. Out of the dozens of sets of headers I've installed, I've never had a set that didn't hit somewhere and need to be modified(pounded on). Never. So plan on it if that's the route you take. You also may have to re-route some brake lines to keep them away from the heat. I haven't done this on my car yet but I plan on it, cause when it starts getting warm from heavy idling, the pedal starts to get soft as the brake fluid heats up.
Assuming your car has a/c like 99% of Cutlass' do, it will narrowly clear the heater box with stock height valve covers. If you have a non a/c car(like me), you will need to make a notch in the heater box to clear the back of the cylinder head. If you run tall valve covers(like me), you'll definately have to do some notching of either type of heater box. If you have no heater box at all, then you have nothing to worry about except getting cold.
Hope that answers some of your questions, let us know if you have more. There's a few of us on here with 455 Olds swapped in. And trust me when I say you're going to love the 455...
The short shaft TH400 and the 200-4R are the same length, and you will only need to change the slip yoke. If it's a long tail shaft, then you will need to have the driveshaft shortened.
Reproduction W-Z manifolds are available, and would be a good way to keep it simple as well as keep underhood temps down. Headers give off a lot of heat into the engine compartment. If you go with headers, Hooker and Kooks are both good choices. Do Kooks wrap around the frame like the Hookers do? You'll need to make some sort of steering stop to keep the front tires from rubbing on the rear primary tube that wraps around the frame rail. Anyways, make sure to buy them painted, not pre-coated. Fit them, pound as necessary, then have them coated. Out of the dozens of sets of headers I've installed, I've never had a set that didn't hit somewhere and need to be modified(pounded on). Never. So plan on it if that's the route you take. You also may have to re-route some brake lines to keep them away from the heat. I haven't done this on my car yet but I plan on it, cause when it starts getting warm from heavy idling, the pedal starts to get soft as the brake fluid heats up.
Assuming your car has a/c like 99% of Cutlass' do, it will narrowly clear the heater box with stock height valve covers. If you have a non a/c car(like me), you will need to make a notch in the heater box to clear the back of the cylinder head. If you run tall valve covers(like me), you'll definately have to do some notching of either type of heater box. If you have no heater box at all, then you have nothing to worry about except getting cold.
Hope that answers some of your questions, let us know if you have more. There's a few of us on here with 455 Olds swapped in. And trust me when I say you're going to love the 455...
Blake442 said:
Actually the 200-4R is between the TH350 and TH400 in overall length, but it's closer to the TH350. You MIGHT get away with the stock driveshaft, but you run the risk of bottoming the yoke on hard bumps.
I read an article in Hot Rod or Car Craft a few years back (tried to find it, but I don't have it anymore) that had all the differences between the PG, th350, th400, 200-4r, and 700-r4 all layed out. I might be wrong, it's happened before, but this was the information I used as a guide when doing my swap.
I run a short shaft TH400 and had to have my driveshaft shortened 3/4". Changed the slip yoke (there's about 3 to choose from, long, med and short lengths, depending on your tailshaft...I had to use the short one).
Hope that helps.
I run a short shaft TH400 and had to have my driveshaft shortened 3/4". Changed the slip yoke (there's about 3 to choose from, long, med and short lengths, depending on your tailshaft...I had to use the short one).
Hope that helps.
joe_padavano said:
hey Joe! i swapped back and forth using a Th2004r and Th350 with the same driveshaft and i had 0 problems..
i have a 455 in my 1983 Cutlass and its almost a direct bolt in to the the 307..but since hes going from Chevy to Olds he needs the frame pads from an Olds engine.. and all the accessories and brackets that follow
May I ask why everyone went off on a 200-4R tangent when his combination is SBC 350/TH350 and going to Olds 455/TH400?
Shouldn't there have been a mention of crossmember differences and choices, the electric kickdown switch that's going to be needed for the transmission, output shaft spline count, other possible issues going from Chevy to Olds? I know we're estatic about an Olds using big Olds power but let's not forget these important things.
Shouldn't there have been a mention of crossmember differences and choices, the electric kickdown switch that's going to be needed for the transmission, output shaft spline count, other possible issues going from Chevy to Olds? I know we're estatic about an Olds using big Olds power but let's not forget these important things.
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