rat infested

I have for the last 3 years run a semi-biult th350 behind my 468ci 1983 camaro the car weighs approx 3800lbs is street driven and with a shot of gas has run over 30 x 10.20 - 10.40 runs no probs at all I have recently broken my prop in 2 at 139mph !! and broke the bell housing whilke i was at it .. anyone any ideas do i build a new th350 around a JW ultra bell and fit the 36 element drum and sprag assembly or just build a pre 1970 th400 with the 34 element sprag . DECISIONS DECISIONS!!

Doug Gulley

I'm no tranny expert but I've always heard that a 400 takes more HP than a 350 to turn. If it were me, I'd call a few manufacturers for their suggestions. Based on your times and car weight, they can get an approxamation of the HP and torque your pushing and give you a recommendation.

Since it is also a street car, depending on how much street use it see's, I'd also look into an overdrive tranny, either a 700-R4 or a 200-4R. Either would give you a deeper first gear over the 350 or 400. The 200 has something like a 2.75 1st and the 700 has a 3.06. The 200 wouldn't have as much 1st - 2nd gear drop. I've also heard that the 200-4R can be built pretty stout.

Sorry if this wasn't the definite answer you were looking for, and may unintentionally on make the waters muddier for you. That's just the things I'd consider if I were in your situation.

rat infested

thanx i hadn,t really looked into 700,s i dont know if it would take the grunt (i'm making 570hp without the gas ) and nearly 1050lbft tQ with gas @ 3200 rpm ) i have sent a couple of e-mails to TCI , JW, Pro-built too see what they say tanks again

Doug Gulley

Wow! That's some grunt with the spray! I'd give them a phone call and discuss in detail your needs. I definitely wouldn't buy a tranny with those needs based on emails.

EvilCartman

iTrader: (1)

Stay away from the 700-R4, it's crappy for drag racing due to it's big step in 1st to 2nd gear ratios. 200-4R would be better if you want overdrive or just stick in a built TH400. The TH400 would be the best bet out of them all I'd think.

BruceEmbry

Hi,
I agree with Doug above. You need to inprove the efficancy of your street thirdgen. Go with either a 200r4 or 700r4. If you really want to inprove performance then switch to the electroinic control 4L60e/4L65e. There are build versions of all of these transmissions on the market. I think anyone with an 82/83 thirdgen who plans on keeping the car should choose an overdrive transmission. Yesterday technology is not going make it in the 21st century with these high gas prices.

I have just decided to swipe out my AAMCO build dependable 200c for an 4L60e electroinic control transmission. The 200c has 120,000+ miles on it now and has been completly trouble free since 1992.

Floor guy

Hard to beat a 400

LT1FUN

An automatic transmission with a overdrive like the 700R4/200R4 would definetely be nice but unfortunately, neither one, no matter how well built, would last very long behind a motor putting out that much torque (very impressive #'s by the way )

I speak from experience having built up (and breaking) the 700R4 in my '93 Formula 4 times in as many years .

There are some companies out there who claim their 700R4's can handle up to 800+ HP but I guarentee you they won't last long.

I have a couple of friends who are die-hard Buick Fans and all run low 10 's to high 9's with their GN's and they all they have to completely rubuild their 200R4's every summer.

Waste of money in my opinion.

I'd reccomend sticking wiith the TH350. If built right, they can handle more power then you'd ever want AND last you forever (well, maybe not forever but you get the idea )

The TH400's are nice too, but won't handle any more power than the 350 will, once they've both been buit up. The only time the 400 is stronger is if you compare them stock for stock.

Besides that, as mentioned earlier, the 400 eats up more power and weighs more aswell.

There are plenty of guys at the shop I take my car to that run as fast as 8's and most do it with the 350 and I have yet to hear of one breaking


Oh, one more thing, (sorry for the long post) but if you really want an overdrive for better performance/better streetability (who doesn't) Have you looked into a Gear Vender's under/over drive unit ??

It basically doubles the gears you have now (basically a 2 speed becomes a 4, a 3speed becomes a 6 and so on) They will handle roughly 1200HP and I know atleast 2 guys who run them and have yet to have any problems.

It's a bit pricey but it still costs less then a 4L80E (also an option but is waaaay too expensive)

Here's the link to Gear Vendors

CLICK HERE


Or you can check out these links aswell:

Raptor 700R4/200R4/4L80 (supposedly can be built to handle 900+ HP but I don't know anyone who has experience with them so I can't comment on them)

ART CARR (one of the best Transmission builder's in the country - maybe THE best

Good Luck !!


My Firebird
My new Daily Driver - '88 L98 IROC

IHI

iTrader: (1)

TH400 without a doubt, consider yourself very lucky to this point with your TH350 that it did'nt go bye bye sooner.

That's just too much power for the internally weak design of the TH350 for any durablity even with the best parts on the market....parts themselves may take some abuse but the way they work togethr internally is where the problems lies. For the 5% extra powr it may take over a TH350, when you start getting into numbers like 500hp/500tq, that minimal amount does'nt mean squat for longevity.

rat infested

WOW sure have hit upon a hot one with this question havn't I thanks guys for such a response I'm still waiting for some answers from the pro's I'm not that bothered about mileage (I'm paying over $8.50 a gallon over here !!!!)

Doug Gulley

$8.50 a gallon??!!!! Whoa....


If you're not worried about mileage then I'd say have a killer TH350 built up.

IHI

iTrader: (1)

Why would anybody in their right mind build a TH350 with the numbers he's claiming?????? This is good LMAO!!!

If your producing numbers anywhere close to what you've stated and are actually asking a question such as this, guess the obvious answer is clear as day

Yeah, stick with a TH350 or 700R4 you'll be money ahead in the long run