im doing a radix 112 buildup, want to make over 500rwhp. I currently have a t56 with an ls7 clutch. my rear is a 9" with 4.11's.

I was thinking of going auto, but here are my concerns...
price- would it be more cost efficient to get a built 4spd auto or t-350/400. what would it cost to have either of these built to withstand that much power, also figure in a stall of say 3500.

gears, i would probably want to go with some taller gears...3.70?

what is a t56 with 45k on it, an ls7 clutch and an aftermarket hurst shifter worth?

would I gain anything at the track switching to an auto?

 

I got rid of my semi built T56 for an auto because the shop that built my TH400 gave me an AWESOME deal!

An equally built T56 would have cost twice as much WITHOUT the clutch.

I went with a th400 with all the goodies (minus Tbreak and RMVB). I'm building a highway car though, not a stop light to stop light or track car.

I would suggest a built auto. Depending on use 4L80 seems to be the all around winner, but costs shows. Th400 for the budget minded

 

Honestly my Camaro has been boosted for a while and have made several mid ten second passes on it, 1.4x 60 foots. It works, only reason it's coming out is.. Safety, I'm going from stock shortblock with 67mm turbo to.. Built 408 with 88mm turbo. Needless to say, the expected power jump would make the car less safe trying to shift a 6 speed.

 

I currently have had no problem running my M6 with the power I have, If you are just worried about the M6, In my old setup I ran a 10.98 w/ 408 and 150 shot and 6 speed. An that was with 680hp on the bottle

 

It would be fun with the supercharger and the 6 speed. If it was a turbo build I'd say go auto no question, but the way it's going to make power rather than build it like a turbo does, I think I'd leave it first and see what you think before making drastic changes when they're not more of a necessity.

 

think the ls7 clutch will work ffine? how about my gears? 4.11's seem a little low for a sc.

 

ls7+ boost+ track is bad...

they get hot and require a good cool down between runs. I switched to a spec 3+ and it worked great. I was running around 618/695 through a stock 100k t56. the spec worked great but I was changing the fluid alot. If your going with turbo I would do the auto. "I only want 500hp", turns in to "well on low boost it's 650" real fast...

 

Street car or track car? I'd try the T56 first for street car, switch if a track car. With no OD you will burn a lot of gas with T350/400 and loose converter.

Before changing gears, need to calculate your trap speed and plot against max rpm in 4th gear. Selecting gears is basic math - not an arbitrary decision.

 

A 4l60e from flt stage 5 is 2500 bucks if you have a core. Plus with a 4l60 you have the o/d so you can cruise down the highway witch helps make it more streetable. I personally wouldnt run a non overdrive tranny unless I was building a strictly race car.

 

it will mainly be a street car, so it will only go to the track a couple times a year, ill probably swap out the 4.11's eventually, but like you guys say, ill try it with my setup now and go from there.

 

Autos are good for winning races. But if you do go auto, dont buy a 4L60.