Engine/transmission swap power questions
08-31-2011, 12:52 PM
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Engine/transmission swap power questions
I searched around and couldn't really find what I was looking for, so here goes.
I'm building a 350 that I hope to make 350hp with, and I have a V8 700-R4 from a 305, and I'm kinda worried about blowing the transmission up. Should I be? I'm thinking I'm gonna make 375 ft/ilbs or so. I haven't been able to find reliable torque ratings for the 700-R4, I saw someone said it was 330 ft/ilbs, but i know that the L98 makes 345 ft/ilbs in 90-92 cars so that can't be, theres no way that GM would allow a transmission to be sent out into the wild with more power than the stock components could handle.
So does anyone know reliable numbers?
I'm building a 350 that I hope to make 350hp with, and I have a V8 700-R4 from a 305, and I'm kinda worried about blowing the transmission up. Should I be? I'm thinking I'm gonna make 375 ft/ilbs or so. I haven't been able to find reliable torque ratings for the 700-R4, I saw someone said it was 330 ft/ilbs, but i know that the L98 makes 345 ft/ilbs in 90-92 cars so that can't be, theres no way that GM would allow a transmission to be sent out into the wild with more power than the stock components could handle.
So does anyone know reliable numbers?
08-31-2011, 01:06 PM
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Re: Engine/transmission swap power questions
Exactly:
Some 700s will survive behind ALOT of HP. Some are already garbage and won't work right with one HP. It depends on how it was built, what parts are in it, how many miles are on it or other measures of how much of its lifetime has been consumed, and so on.
Yesbasic junk stock one, no. A standard "rebuild" by the local trans shop, probably not. (at least for very long) Hack jobs that you hear about all the time, crap shoot. Ones built by someone that knew what they were doing using good parts, quite possibly.
So, it depends on the 700 you're talking about.
Some 700s will survive behind ALOT of HP. Some are already garbage and won't work right with one HP. It depends on how it was built, what parts are in it, how many miles are on it or other measures of how much of its lifetime has been consumed, and so on.
Yesbasic junk stock one, no. A standard "rebuild" by the local trans shop, probably not. (at least for very long) Hack jobs that you hear about all the time, crap shoot. Ones built by someone that knew what they were doing using good parts, quite possibly.
So, it depends on the 700 you're talking about.
08-31-2011, 01:15 PM
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Re: Engine/transmission swap power questions
So how do I fix this? lol Do I need to get a valve body kit like this?
http://www.summitracing.com/parts/TCI-376000/
And what about putting in a shift kit? What will it provide me for the money I'll spend on it, and will it make the transmission any stronger? The transmission is rebuilt with 5K miles on it, but it was for a 305, and I don't want to blow it up putting a 350 in front of it.
http://www.summitracing.com/parts/TCI-376000/
And what about putting in a shift kit? What will it provide me for the money I'll spend on it, and will it make the transmission any stronger? The transmission is rebuilt with 5K miles on it, but it was for a 305, and I don't want to blow it up putting a 350 in front of it.
08-31-2011, 06:44 PM
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Re: Engine/transmission swap power questions
My point was and is that there really isn't any way to predict what any particular 700R-4 will survive. A bit of reading through old threads, you'll notice how many people have problems with 700R-4s even with stock 305s.
A 700R-4 can be built into a good transmission. And the '88-up 700R-4s typically made it through their original warranty mileage without any issues.
Beyond that, they're unpredictable.
Do all the upgrades you can afford, you might still have problems. Leave it alone, it might survive occasional nitrous. You just can't predict any used 700R-4.
A 700R-4 can be built into a good transmission. And the '88-up 700R-4s typically made it through their original warranty mileage without any issues.
Beyond that, they're unpredictable.
Do all the upgrades you can afford, you might still have problems. Leave it alone, it might survive occasional nitrous. You just can't predict any used 700R-4.
08-31-2011, 08:38 PM
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Re: Engine/transmission swap power questions
Haha alright I'm just trying to think of every possible thing for my engine swap. I'll probably end up getting it oversized servos, a shift kit, and a the valve body kit and that should make it handle what I'm going to throw at it. Its not like I'm building this for a racer or drag strip car or anything, its just going to be my weekend/nice weather car thats going to take some occasional beating.....
My 4.3L S10 Blazer has 233,000 miles on it and its still using its original 700-R4, and I do not take it easy on that thing, I beat the hell out of it on trails and use the 4x4 a lot in the winter and it shifts perfectly time and time again.
My 4.3L S10 Blazer has 233,000 miles on it and its still using its original 700-R4, and I do not take it easy on that thing, I beat the hell out of it on trails and use the 4x4 a lot in the winter and it shifts perfectly time and time again.
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