I am building a 350 engine out of a 95 truck. it will have somewhere in the range of 375-425 rwhp. i want at least 10mpg, if not more. the question is would it be better to go with the six speed so that i have that extra gear or it doesnt make a difference. also is the concern with the torque arm and the crossmember for the transmission. is it that much more work to put in a t56 than a t5.

 

Into what?

The T-56 is heavier; so from that point of view, it's more work because it takes more effort to lift it. Number of bolts is about the same though. Not sure what you mean by "more work".

 

What kind of car do you have? Year?

Whats better? Well a lot of that is a matter of opinion. T56 is stronger and of course will get you better mpg on the highway. T5 is weaker, but lighter, and i believe it also has a steeper first gear that matches more of a 700R4 automatic, ill have to dig through some notes i have it that is correct i forget them easily. So if you build a T5 to hold the hp/trq it could do much better then a T56 on a race track.

Which is more work? Well depends what year and what kind of car you have, cable driven speedos require more work to work with a T56 and more money. T5 can use the stock automatic crossmember where as the T56 requires a custom aftermarket crossmember. Driveshafts/Trq Arms are the same for each tranny.

Only real difference between a T5 and a T56 swap is the speedo, different crossmember, and about a 2" bigger hole in the tranny tunnel for the shifter other then that its the same swap.

 

i have a 86 iroc z and i want to go with the t56 but at the same time i want to buy tranny,pedals,hydros, and everything i need to swap from one buyer. but thanks for the advise

 

No question the t56 out weights the t5 in every way, T56 much better and well orth the expense

 

well if you know anybody who has the whole set up let me know. i need to get rid of a set of 22's chevy 6 lug pattern or if you know someone willing to trade please let me know that would be great. thanks for all the info i think i am going with the t56.

 

ck the 4th gen boards loke z28.com, camaroz28.com and ls1tech.com those would be the best place to look

 

so all you have to do to fit a t56 into a 89 camaro that had a t5 is a crossmember and speedo issues? the slave cyl. for clutch and drive shaft will all fit?

 

as long as you get all the needed hardware and flywheel off the doner car yup, it will bolt right in (ex the crossmember and speedo)

 

T5's are deffintiely weak. I am one of several who have abused them well beyond what they're rated for, but they will come apart sometime, even with the upgraded parts. The case is just too weak. It's weight is the death of it.

All that said, I would hope you get better than 10mpg out of it. I was getting 15+ in town and 20-21 on the highway with a T5, 3.73 gears and a carbed motor making somewhere around 500hp. - it's all in the set-up. The gearing, cam choice, trans ratios, etc, etc, etc.

 

hey guys i thank you for all the information and i decided to go with the t5 because of the fact that it is lighter and alot cheaper to rebuild if i blow it up. thanks again for the information

 

like I've said a million times, "If you can't afford to do it right the first time, can you afford to do it again?" and in this case, again and again and again.....

if you use a decently built T56 you won't have to worry about it again for a long time. A T5 will require much more than a rebuild after you break it. When it goes it'll take out the cluster and which ever gear you happen to be in. It usually weakens the case thus the whole thing is junk.

to each his own....

 

If you go T-5, you better plan for less HP/TQ if you want it to last.

 

for that engine, theres only one reasonable choice between thoes two transmissions....


the T56.



the T5 is really a POS for a performance transmission... even if you replace every piece in it with the best possible parts..... it'll break with a decent street motor.


either get the T56, or plan to get it eventually.