I am wondering what the stock MG5 5 Speed trans out of a late model gm with a V6 or a 4.8 is worth power wise. I do not know if the joe gibbs trucks have the same trans or not, but that would be a help to know. I am curious because I want to swap a 5.3 or a 6.0 for my stocker 4.3 and would like to run the stock 5 speed for a while until I can get a T56 for it. My driving style is fairly tame, I would not be doing any 3K rpm launches or anything like that, just daily driving and an occasional smoke show here and there.

 

it should last

a couple have blown them out with boltons but turbogibbs never broke his with a radix'd 4.8

so its kind of a hit and miss type thing

JGP trans is the same , i think it has different clutch?

 

Manual trannys strength all varry on how you abuse it. You can break one with a 250hp engine or one will hold up behind a SC 4.8 with 445rwhp and go a 12.58 @109 with a stock clutch. A 95 model MG5 will hold up to a 383 SBC 10:1 comp, 240/250 110lsa .575" cam and 150hp shot of nitrous.
Just speaking from experience. You will find some people preach about how they are junk but from what I have observed they must try to break them.

 

JGP has the same stock clutch, or at least the N/A models do like mine was from the factory. Keep in mind it is a 12" clutch and designed to tow. They are much stroger than a F-body 11" clutch designed for a 300hp engine and 3500lb car and no towing.

 

Thanks turbogibbs, thats right along the lines of what I was thinking. I know a T56 is optimal, but it's just not in the budget at all right now. Ill run it and see how the stock step-up works, and I am sure it will be fine for what I do.

 

i agree with gibbs i have seen a few 5 speeds in f bodys with 383 and one with a 400 both were street/race cars and both ran dr all the time and held up for a good long time i would not be scared to do it.

 

I would think the limiting factor is the torque rating. In reality, an F-Body pushes about 350 foot pounds as many deliver about 305 - 310 at the rear wheels. I don't think the 4.8 produces that much