BenUK

Thinking about getting a crate engine. Budget stretches to 430hp+ / 450ft-lbs but I'm wondering whether my (original?) 1976 Borg-Warner T10 4-speed will handle that kind of power unmodified.

Anybody got any idea?

I think the 'box is in pretty good condition. Had the cover plate off a few years ago and didn't see any wear on teeth. Oil is clean.

TIA

chewy

You will have rear end problems first. It is the weak link in the drivetrain.

panic

ben, i have exactly your very same 4 speed trans in my '77...i have a 406ci giving a healthy dinoed 570hp and 530tq figures at 6.300 rpm...3.000 miles already and my T-10 still holding fine this power level, i cannot guarantee for tomorrow but up to know they steel guy is still enjoying every drive

Billysvette

He is right on .Ive been through serveral rears,and i run richmond t10 with about 600hp.the rears in our cars are the weak link.

MotorHead

Couple hundred less than what I have I blew 2 Super Duper T10's in short order when I installed my 550HP/510TQ 406ci. I think they are rated at less than 300ft/lbs THe main reason I went to TKO 600

spedaleden

I have a 400 hp motor with stock 4 speed and rear end. Everything is fine. I am going to a 5 speed tremec, 1981 4 speed gearing is a dog around town, but great for interstate driving. I don't know about a 1976. My rear end gear is a 2.72. I am goin to change to a 3.55 with tremec.

My neighbor is a service manager at Chevrolet, I was told as long as I don't dump the clutch at 4 or 5 thousand rpms the driveline should be fine.

BenUK

Cool. Thank you all for your replies.

I'm guessing that my BFGoodrich tyres are going to break traction long before any mechanical components give up, but if the rear end is the weakest link then at least a broken diff gives me an excuse to change the ratio to something better for top end.

Found a hp / ET calculator online earlier. Comes out at 12.4 secs, with a 0-60 of 4.28 secs.

MotorHead

OK here is what I was told and I believe it. Iron case T10 can handle more power, but probably not much. What kills them is not so much dumping the clutch at 5000 RPM but sustained torque.

Especially in the aluminum case versions like what I had in my 80. Putting 500 foot/lbs through it with a torque curve similar to mine ( near 500ft/lbs from 2000 RPM to 6000 RPM ) twists the case and throws everything out of line for a period of time. Second gear for some reason is usually the first to go ( he said this before I told him that it was indeed second gear that was blown....first )

If you guys have all that power and aren't blowing a tranny rated at 300ft/lbs then something is up. I would not put one behind any serious motor unless it was the only thing I had

Billysvette

I have had my richmond t10 rebuilt ,miner repairs.The guy that rebuilt it said that it was heavier duty then regular t10s.Maybe thats why mine has lasted this long.On another note ,when i get time and money im changeing to a custom built auto w overdrive.I also have cut back the horse power,too much brakeage.

MotorHead

My 80 had a 2.88 first gear with 3.08 rear end

63mako

A lot depends on the first gear ratio. These were available in quite a few ratio's The strongest is the 2.42 low ratio. I think they had a 3.42 first gear ratio in the late C3 cars to help pull the 2.87 rear end with under 200 HP. Those won't handle much power.They have a wide ratio between gears and it stresses the trans a lot more between shifts. The 2.42 low trans is good for well over 400 HP but you can break anything if you abuse it. I think the tires will break loose first. I would use it if it is the close ratio Super T-10. I am using an Auto Gear Muncie Super M-22 Rockcrusher in mine. You need 4.11 gears with it and it revs pretty hard on the highway, but you won't break it.

63mako

Yep! You are right, I could see you eating up that trans. The 3.08 offloads a lot more stress on the trans than the lower gear rear ends and that motor is a beast! It would hold up a lot better behind a 3.70 or 4.11.

slowup

no such thing.

bence13_33

I run that same 4 speed transmission in my '76 Corvette w/ my 468 big block. I used to run slicks and drag race a good bit and never had any problems. It's a stronger transmission than most give it credit for. My motor is around 550 horsepower. I also wanted to add that I ran 12.1 @ 118mph with that transmission and the old version of my motor seen below.

BenUK

Thanks again. I guess the thing to do is try it and see... :o