350 Swap Question
#1
350 Swap Question
Hello,
I'm looking to swap the tired 305 in my 84 Trans AM for a 350 Vortec out of a 98 Silverado. The roller block in I'm thinking about installing is a one piece rear-main. Will that bolt up to my 84 700R4 Tranny or will I need to get some parts and/or modify anything to get it to fit? Thanks!
I'm looking to swap the tired 305 in my 84 Trans AM for a 350 Vortec out of a 98 Silverado. The roller block in I'm thinking about installing is a one piece rear-main. Will that bolt up to my 84 700R4 Tranny or will I need to get some parts and/or modify anything to get it to fit? Thanks!
#2
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
You'll need a 153-tooth flexplate for one-piece rear main seal, such as used in '86-up 3rd gen V8 auto. The truck is most likely 168-tooth, which may fit the tranny (most likely it's got the dual pattern converter mount pattern), but needs the 168-tooth starter which sits farther out from the engine and can interfere with 3rd gen exhaust.
#3
Re: 350 Swap Question
You'll need a 153-tooth flexplate for one-piece rear main seal, such as used in '86-up 3rd gen V8 auto. The truck is most likely 168-tooth, which may fit the tranny (most likely it's got the dual pattern converter mount pattern), but needs the 168-tooth starter which sits farther out from the engine and can interfere with 3rd gen exhaust.
I'm currently running Hooker 2055's which, when looking at it, seems to have quite a bit of room between the exhaust and starter.
#5
Re: 350 Swap Question
So just make sure I buy a 153 tooth flexplate and I'll be good then? Also, I was talking to a machineist and he said that sometimes with the one-piece rear main seal motors, something is different on the block that may not allow it to bolt up to my tranny...that true or will this thing line right up?
Last edited by Ozz1967; 03-26-2008 at 07:28 AM.
#6
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
As long as it isn't the LSx style engine, you won't have any problems bolting up the tranny. A '98 won't be any problem at all.
Except I just remembered they often don't have the fuel pump mount drilled/machined, so you might have to install an electric fuel pump.
But that isn't a transmission problem.
Except I just remembered they often don't have the fuel pump mount drilled/machined, so you might have to install an electric fuel pump.
But that isn't a transmission problem.
#7
Re: 350 Swap Question
As long as it isn't the LSx style engine, you won't have any problems bolting up the tranny. A '98 won't be any problem at all.
Except I just remembered they often don't have the fuel pump mount drilled/machined, so you might have to install an electric fuel pump.
But that isn't a transmission problem.
Except I just remembered they often don't have the fuel pump mount drilled/machined, so you might have to install an electric fuel pump.
But that isn't a transmission problem.
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#8
Re: 350 Swap Question
As long as it isn't the LSx style engine, you won't have any problems bolting up the tranny. A '98 won't be any problem at all.
Except I just remembered they often don't have the fuel pump mount drilled/machined, so you might have to install an electric fuel pump.
But that isn't a transmission problem.
Except I just remembered they often don't have the fuel pump mount drilled/machined, so you might have to install an electric fuel pump.
But that isn't a transmission problem.
The 4-bolt block is According to the casting number not an LSX motor so if I get a 153-tooth flex plate, I should have no problems bolting it strait up to my tranny and starter. Will I have to get a new starter or will the one from my 305 work with the 153-tooth flexplate?
I'm going with World SPortsman II heads which will be modified for EGR.
I am going to try and find a stock rotating assembly (Crank and rods) and I would like to get some new Kieth Black Silvolite pistons to pull 9.1-1 or 9.3-1 compression. As this is a daily driver I need to be able to run 87 octane.
I've already got headers and a cat-back on the car now.
I'm keeping my Q-Jet and upgrading to an Edelbrock Performer intake (EGR)
Is there anything else I'm missing or that I haven't picked up on yet that I need? Thanks for any help!
#10
Re: 350 Swap Question
Because I'm building a 350 while I drive the T/A. If I parked the T/A then I could pull the motor and scavenge the Crank and Rods. In fact that would probably make sense wouldn't it? The crank and rods should be the same as I would get for a 350. Hmm...
Last edited by Ozz1967; 04-20-2008 at 01:50 AM.
#11
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Are you picking up an engine, shortblock, or bare block?
If it's an engine, it will have Vortec heads (are we still talking about the '98?). The crank and rods should be fine, unless it's for sale because of a wiped out bearing or something like that.
If it's an engine, it will have Vortec heads (are we still talking about the '98?). The crank and rods should be fine, unless it's for sale because of a wiped out bearing or something like that.
#12
Re: 350 Swap Question
The guy who was selling the long block sold it about an hour before I told him I would buy it. Instead I wound up getting a 4-bolt bare block, casting number 10243880. It looks to be in good condition, no obvious cylinder damage and I couldn't find any visible cracks or the like. I'll take it to the shop tomorrow and have them clean, magnaflux etc. Then it's out of my hands. I'm just going to tell him what I want and let him do his magic.
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