Olds 350 to Chevy 350 Swap

565bbchevy

Geezer
Aug 8, 2011
9,614
12,683
113
Michigan
Getting confused and irritated. motor is in, mounts are tight and as far forward as they'll go. distributor is on the firewall,
Did you have rubber isolators under the trans cross member when you removed it? If they were there originally and not reinstalled it will let the engine lean back a little towards the firewall.
 

zipties

Apprentice
Feb 2, 2022
73
45
18
Did you have rubber isolators under the trans cross member when you removed it? If they were there originally and not reinstalled it will let the engine lean back a little towards the firewall.
Nope, just nuts and bolts. I'll probably need some... guess it makes sense to undo the xmember, get a big piece of cardboard and a jack, and bolt the trans to the block first. Then I can get the member sorted.
 

zipties

Apprentice
Feb 2, 2022
73
45
18
big necropost. cannot believe its been like a year.

i resold the vortec 305 and cored out the BOP trans. have been super busy with a lot of other things in life and forgot about the thread. I stay pretty active on CGBG on fb, checking stuff out and giving advice where i can. between this cutty, my elco, my wife's squares, our dailies, and all of my friends and family's cars, i stay very busy.

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cutlass is coming along nicely. quick pics of what i've been doing, which is cleaning, sourcing parts for the car/motor, and painting.

i still need to finish painting the motor and mate it up to the new turbo 350, then bolt it in once i've sealed the frame up.

only parts i need now are a new dizzy and mini starter, which should be about $300. considering how long its sat now, i'm thinking of dropping the tank and just getting a new one. If anyone has recs for a good replacement tank, please let me know.

here's how everything sits as of today:

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thanks for checking out my junk. heres hoping i get it back on the road before summer's over
 

78Delta88

Royal Smart Person
Supporting Member
May 23, 2022
1,307
1
1,095
113
SW Arizona
Which tank are you looking for. I can see what's available. I know 78 regal, 84 Cutlass available. I have to check on the rust, but I know in my 86 no rust, just a bunch of dried on crud from bad gas. My cutlass sat 12 Years under a tree before I picked it up.

On the mockups. I just use empty 305 block with oil pan and gutted th350 shell, output shaft still installed but everything else gutted out of it.
 

zipties

Apprentice
Feb 2, 2022
73
45
18
Which tank are you looking for. I can see what's available. I know 78 regal, 84 Cutlass available. I have to check on the rust, but I know in my 86 no rust, just a bunch of dried on crud from bad gas. My cutlass sat 12 Years under a tree before I picked it up.

On the mockups. I just use empty 305 block with oil pan and gutted th350 shell, output shaft still installed but everything else gutted out of it.

any stock tank that'll fit. i know already there's no more G bodies in the yards close to me with parts worth taking. Only thing left is a 78 monte with a floor shifter that i probably wanna take, other than that it's smashed up 4 doors and stripped bodies. sucks that for parts i have to either buy new and ship, or travel hours to a better yard.

used to have a rubber ducky, one of those fancy mockup blocks, but not enough space. i tried working on the cutty outside as much as possible since i like to use the bay for my emergent issues or friends' cars, but didnt feel like doing any more motor mockup on gravel. Should be one and done anyway, if this anything doesn't fit i'm just getting the hammer out
 

zipties

Apprentice
Feb 2, 2022
73
45
18
frame has been coated and cured, finishing up the clear on it and the block this weekend.

things i need to get done this weekend:

replace filter, gaskets and seals on the new 350C trans
get a new oil pan bolt (existing bolt is very sketchy)
get all the fittings for gauges/sensors installed
remove and clean driveshaft
test fit engine and trans (going to bolt trans to the block externally, and install as one)
check tolerances for headers, oil filter, starter+wires, dizzy, air cleaner with intake, etc.

if it all looks good, i'll get the drivetrain mounted up permanently.

I was refurbishing an edelbrock intake for it but it was pretty gutted, and i don't want to waste any money/tools on it, so i got a holley on marketplace that should arrive saturday. power of the internet. paid 60 for it, not a bad deal.
 
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1320chevy

Apprentice
Jun 23, 2023
51
39
18
Hey, I'm sure this has been done a million times but I didn't see any recent threads and don't like reviving old posts so here's a new one.

I got my hands on an SBC for my 78 Cutlass after pulling the Olds 350. I removed most everything from the engine bay to prep it. I have a general idea of what needs to be changed/modified for this swap, but help never hurts.

View attachment 204263

I'm going to retain the BOP trans for now and have an adapter plate. My question is which flexplate I need to use, the Olds or the Chevy? I got the JEGS adapter, but I see discussions about needing spacers or even making clearance in the bellhousing. What's necessary for that?

View attachment 204262

I redid my wiring harness and it's in good shape. Guessing I need to extend my starter wires since they're on opposite sides, are there any other wires that need modified or added?

Part numbers for whatever I'm forgetting would be a big help - I need motor mounts for sure. I already have everything ready for the SBC (i have buckets of SBC junk which is part of the reason for the swap) so not worried about that. Just want to make sure I have all the swap stuff covered.

Thanks in advance. FWIW the Olds motor still hasn't been claimed if anybody is in need of one, hit me up.

Hey, I'm sure this has been done a million times but I didn't see any recent threads and don't like reviving old posts so here's a new one.

I got my hands on an SBC for my 78 Cutlass after pulling the Olds 350. I removed most everything from the engine bay to prep it. I have a general idea of what needs to be changed/modified for this swap, but help never hurts.

View attachment 204263

I'm going to retain the BOP trans for now and have an adapter plate. My question is which flexplate I need to use, the Olds or the Chevy? I got the JEGS adapter, but I see discussions about needing spacers or even making clearance in the bellhousing. What's necessary for that?

View attachment 204262

I redid my wiring harness and it's in good shape. Guessing I need to extend my starter wires since they're on opposite sides, are there any other wires that need modified or added?

Part numbers for whatever I'm forgetting would be a big help - I need motor mounts for sure. I already have everything ready for the SBC (i have buckets of SBC junk which is part of the reason for the swap) so not worried about that. Just want to make sure I have all the swap stuff covered.

Thanks in advance. FWIW the Olds motor still hasn't been claimed if anybody is in need of one, hit me up.

I am just saying long term you might regret removing the AC, I wish I would have somehow kept the AC in my Monte with the BBC but the engine physically doesn't fit with case in there but I installed a heat only case to give me clearance because I can not stand the look of a block off plate especially in a SBC car where the engine fits with no clearance issues, once it's gone it is 3 times the work to reinstall. JMO
Normally, before I attempt a swap from GM to GM vehicle, I check to see if that car was also made in Canada. Often you'll find a Canadian version that has the power plant you intended to swap in as standard". If so, ordering stock parts is far easier than finding conversion stuff.
 
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565bbchevy

Geezer
Aug 8, 2011
9,614
12,683
113
Michigan
Normally, before I attempt a swap from GM to GM vehicle, I check to see if that car was also made in Canada. Often you'll find a Canadian version that has the power plant you intended to swap in as standard". If so, ordering stock parts is far easier than finding conversion stuff.
I don't think it really matters where it was made, only what engine is currently in the car when you get it and for putting an SBC in a B.O.P. you don't need conversion parts just order for the same year Monte with an SBC if you want to run stock parts.
 
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zipties

Apprentice
Feb 2, 2022
73
45
18
I don't think it really matters where it was made, only what engine is currently in the car when you get it and for putting an SBC in a B.O.P. you don't need conversion parts just order for the same year Monte with an SBC if you want to run stock parts.
yeah i don't really think it's a big deal to just order for a same year monte. only thing that comes to mind where this woukd matter would be like for one of my squares, it was a canadian truck so it was in km.

anyway its humid this weekend but i got the final coat of hi temp clear on the motor, started some mockup of all the fittings and lines for peace of mind. I did realize my fuel inlet is basically gonna contact my heater hose, so I'm gonna work on making a new hardline to route it away.

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I'm really happy with the paintjob personally. i was really impressed with the patina and amount of OE paint on the block and didn't want to just burn it off and let it go to waste. a perfectly clean and paintef motor won't look right in the car anyway. made it take extra long but should end up looking killer when it's all bolted.

with that said, i can't decide on just painting the engine bay black or doing it in color. it has to be painted anyway so there's no way around it. personally I'd like to go with red, if anyone's got a G with a color painted bay lemme see it.
 
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