Hello gents,

I am planning on replacing the nice-weather street LO3 in front of the weak sister T5 with a mild pump gas 400 sbc.

(Carb'd with a 700 mech-sec Holley, non-computer HEI, 3" Hooker cat back, Hooker 2055's, block drilled for a straight-across starter etc.)

I know the T5 is a hand grenade waiting to happen, but daughters' tuition wins out over a T56 for the time being.

So, has anyone granny-shifted their way into the 13's with a tall rear end and the requisite low rpm torque?

 

I'm sure may be able to get a few runs in the 13s but I would not push a 5speed to much. they do not like to be slammed hard and the do not like a bunch of power.

 

Maybe one time.

 

Sure it’s possible, but it won't last long in stock form. Some people are using the upgraded T-5 from G-force transmissions. The T-5 has its benefits though. Its light weight and the GM style transmissions fit in our cars with no mods.

The down side is what others have mentioned. They don't like to be speed shifted and when the power goes up, they have serious problems. Remember that GM put the T-5 only behind the LB9 and not with the L98 because of the torque capacity problems. I think the world class T-5's have a max torque rating of around 300 foot pounds. The non-world class T-5's are a little less than that. At the end of our cars run the LB9/G92/5-speed cars were rated at 230 hp and 300 foot pounds. The L98 was rated at 245 hp and 345 foot pounds.

A wise move would be to save up for a TKO 5-speed tremec style transmission or a T-56. Moving up from an L03 to an engine that will easily have a significantly more power than a stock L98 will lead to a short life for a T-5. You can do the 400 swap but you may want to baby the T-5 for a little while if you do.

 

I ran a 12.7 @ 111 in a 92 w/ 355, T5, 3.23's, and 275-60-15's. 2.0 60'. I never even shifted into 4th. Through the traps at 6000 in 3rd gear.