I got a few qustions about this setup im thinkning about. my car is an 85 Z28 w/ a LG4, auto...blah blah....i want to put in a rebuilt 350 w/ 350 hp, and a turbo 350 transmission. i dont know much about th350s, but will 3.73 gears work well with it or should i go with gears more like 3.42? ive heard w/ 373s and no OD, it will top out at like 100. is that true? the car wont be a daily driver, but i still plan on taking it on semi long trips ( 80 miles @ an average cruise speed of 40 ). well thanx in advance.

 

Why dont you just use the tranny thats in the car now?

 

I'd almost never recommend removing an OD trans and going back to the old-tech TH350. It's a pain to put in a trans that was never designed for the car in the first place and it's really no better than a 700R4 in terms of strength anyway. One time I'd recommend it: for a strip-only drag car. Other than that, forget it.

And 3.73s on the street without OD is miserable. An 80 mile trip at 40 MPH? For real? Not me baby. 80 MPH on an 80 mile trip is how I do things. And you will NOT be cruising at 80 MPH with 3.73 cogs in the back end. Even at 60 you'll be spinning the guts out of the motor pretty bad.

WITH OD, however, 3.73s are livable.

 

Hey,

Ive got 3.73 with a 350 and th350. Dont even plan on going on the Highway. 80 thats a joke unless you want to redline. Im probably goin 50 at 4000 rpm. Very bad gas mileage also.

 

<350/TH350/3.42 65MPH cruise is about 3,000RPM 10MPG. If I drop it down to 2500RPM (about 45-50) just above the stall of my converter I get 20-25MPG.

 

Just to give you an idea with the 350 3:73 combo. I can let my car idle (around 1500 rpm) and it will shift into second.

 

They used to build cars like that all the time.... I had a 79 Z28, 350/4-speed/4.10s; another Z28, a 78, 350/350/3.73s (that was the stock combo in the 78); I have a 74 Caprice convertible, 454/400/3.42s.

Sounds OK to me.

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"So many Mustangs, so little time..."
ICON Motorsports

 

I agree.I have seen quite a few th350/3.73 combos,especially if it's not your daily driver.I have 4.10's in mine,I can cruise but forget the interstate!later

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"Let's get to it,well let's do it!"

 

what do you mean a TH350 isnt stronger?

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Wide Open Till You See God...Then Brake

 

No, stock for stock it's no stronger than the 700R4. They are weak in different places, but overall, about the same strength wise.

 

Don't you mean 40 miles @ an average cruise speed of 80?