I need a tranny!!!

[69GMC910]

Funny title hey!!! lol!

My current setup is an 82 LWB with a sbc, TH350C, and a 10 bolt diff. The new engine is a BBC making 700hp. There is another post about rear end choice already, and I'm pretty sure I'm going to get a Moser 9". Now, I need a transmission that will handle the power as well. My TH350C has a 9" tailshaft, and I want to swap to a TH400. I called about a TCI and they offered me either a 4" or 9" tailshaft. Other than length, what's the difference?? Probably better to have a shorter driveshaft anyways??

Other than TCI, what would you recommend? I priced locally for a ground up build 400 and it was $2k more than the TCI I was looking at...

I can NOT spend more than $2000 on the transmission!!! I'm getting a 10" 3000rpm converter made for it so I don't need one of those...

Please help!!!

[BigDan3131]

Is this a dyno proven 700 hp or just a best guess? A properly built TH350 can handle up to 700 hp. I have a TCI Street Fighter I freshened up and then talked to tech about how much power it can handle. He told me the only difference between the Street Fighter and Super Street Fighter is the SSF has a manual valve body and can take 700hp max. Its mostly the drum and sprag. You will lose up to 20-30hp going to the TH400 I think that's what I heard.

[Marv D]

Hughes street strip TH350 with a Jeggs house brand (rumored to be Art Carr) 3800 stall convertor. Total shipped to his door was just under $1400 (back about 5 years ago,, probably a couple hundred more now) He's been throwing a honest 700HP at it with a 10" slick. Footbraking a 3300 pound car to 10.teens. 5 years, nothing but a fluid and filter change every couple of years.

I couldn't agree with BigDan more,, built RIGHT,, the TH350 will tolerate a LOT. NEVER come out of the burnout in 2nd gear will go a long ways towards it's survival too.


If your dead set on a TH400,, either one of these would serve you well IMO, The $2000 one being built for blown applications ought to tolerate anything you throw at it. But if your not looking at slicks, or LOTS of track time,, the $1100 version is hell bent for stout.

[69GMC910]

It will be a very honest 700hp engine... The builder also says he runs 1200hp through a 350 and it still hasn't blown up... I do plan to have "some" traction. Will traction be it's biggest enemy?? The 350 is so much more appealing cuz it would bolt right in...!

[69GMC910]

Does the fact that the Hughes transmissions are not SFI approved matter?

[djracer]

Do what you want to but I wouldn't put a turbo 350 in a heavy truck with power. Its a huge difference when you add another 700 plus pounds of vehicle weight. I tore up several torque convertors in a street strip truck I had till I had someone take the weight into consideration.

I would go 400 and forget it.

[Marv D]

Originally Posted by 69GMC910

Does the fact that the Hughes transmissions are not SFI approved matter?

The SFI requirements are all dependant on the ET / MPH you run. I don't believe there are any liners to get a stock TH400 case SFI approved. In fact the only SFI TH400 case I have heard of is a JW Ultra Case,, but that doesn't mean there arent others.

At 10.99 and quicker you have to have a trans shield and flexplate shield,, OR a SFI case. Dedenbear, ATI, JW, Reed,, number of SFI Powerglide SFI approved cases,, But 350's and 400's are pretty rare in the real quick classes.

[djracer]

You should be able to get external shields if you ever go faster than 10.99.

[KQQL IT]

My dad always said if you dont hook it.
You wont break it.
That being said ive killed t350 input shafts with a 400 sbc
My 400s usually only need clutches and wear parts.

[69GMC910]

I ordered up a super street fighter th400 today... Should handle all I can throw at it!
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[djracer]

Good Move!