4L60 to weak for a small block?

camoxj93

New Member
Joined
Jul 28, 2012
Just wondering if anyone has had any luck with a small block in front of a 4L60? am i just building a time bomb by even putting a 305 in front of it? id like to go with a moderately built 350. its going in a long box S10 that will eventually be on 35s and used for mud only.
 
The 4L60, it's predecessor the 700R4 and the later 4l60e were all used both in 4cly, V6, and V8 applications. The only difference being the fullsize truck and V8 applications have an extra clutch disk in the 3-4 clutch. Your "mud truck" probably won't be using o/d too often so that shouldn't be an issue. All "hard" parts in the trans are identical between v6/v8 applications. It will survive fine behind your 305 or even a mild 350 if you aren't beating on it, but the 4l60/700r4/4l60e never had a reputation as a bullet proof trans behind any engine if you beat on it. Run it till it goes, then rebuild it stronger. There are a few things you can do to get a little more holding power out of it such as a Corvette servo, that will give firmer quicker shifts (less clutch slip at shift) and more apply pressure. It's something you can do in a driveway in 30 minutes and makes a noticeable difference. A shift kit helps as well without completely tearing into the transmission, also add a bigger transmission cooler to keep things cool.
 
thanks man id heard about the shift kit and servo swap. they are def on the list if i keep this trany. im prolly not gonna flog it to hard as i have with the 4.3 in it. my worries are about case strength to. would it be worth my while to just go with a th350? im gonna be doing alot of other swapping any way like a 10 bolt front and 12 bolt rear and maybe the dana 300 t-case i already got
 
The 10 and 12 bolts will probably go before the 4l60 does. I've seen plenty of 700s and 4l60s in drag cars, mud trucks, and tough street rods. They can be built into the 500hp range with the right builder. The TH350 really isn't much, if any stronger. If you drive it on the road, you'll appreciate the OD anyway.
 
the 4l60 is good for 550hp
the corvette servo has nothing to do with clutch holding power. the servo is for band apply only(2nd and 4th), it will give you quicker firmer shifts though. if it's a 4 or 6cyl 4l60e the pistons will need to be changed so you can add extra clutches.
 
thanks for the info yall. wow 550 transman? this puppys staying in the s10... if i can beef it slowly as the truck grows. catfishblues yea the 10 an 12 are a bit dinky but they are the only thing i can get my hands on right now. an your right about the od it will still see street driving once in a while as i dont have a trailer to tow my toys so od is a huge plus
 
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