I have a 1987 IROC-Z and just swapped out my old TPI 305 for a new 400 sbc wit 350 HP. I knew the stock T5 couldn't handle the added power but budget insisted i give it a try. Well it lasted 2 months. Anyway i'd like to replace it with another 5 or 6 speed manual but im on a tight budget, ive heard that T5 World transmissions might be up to the job... any suggestions? im open to ideas but only have $1000 bucks to throw at it.


thanks for your help

 

I think if you're on that short of a budget your best option is to throw another T5 in. A wcT5 will still break. They're not that much stronger. I mean the wcT5 didnt show up until the late 80s, same as the L98, and GM still didnt think a wcT5 could handle an L98.

But it will last you if you're easy on it... so you can buy a new T5 for a few hundred bucks then save for a T56 which is, IMO, your only real option unless you want to go Tremec or something.

With a T56 you'll need to change the clutch hydraulics, the bellhousing, clutch, flywheel, and crossmember. Your biggest concern is getting the right flywheel for your externally balanced engine, but they are available, although around $300-$400.

$400 for a Flywheel
$800-$1300 for a T56 (with other parts I mentioned)
$300 for a clutch.

I'd say that's your budget.

 

https://www.thirdgen.org/forums/engi...cement-t5.html

No need to replace FW/Clutch/bellhousing/linkage.

 

A friend of mine has been road racing a 396ci WCT5 set up for quite some time now with no ill effects.

The two things he points to are that while the car is obviously abused around the track, the transmission doesn't take nearly the abuse of doing hard drag race launches etc. etc., and second, he's got the right clutch for the transmission. Figure since the weakest link fails, might as well make that the clutch and NOT the tranmission. And to add to that idea, I talked to a guy at Astro Transmission a little while ago about a t5 swap, and he said the same thing. You can't expect the the t5 to survive if the clutch is matched to a high power engine. You have to match the clutch to the t5.

 

Thanks for all the help and info, i guess ive got more research and saving ahead lol. I want to do it right the first time.

 

TKO 500's are 5 speeds that can take a beatinggggg, TKO600 is a 6 speed. id look into those. they are alil bit of $$ but they can be built to your specs and handle some strong #s

 

actually the tko600 is a 5 speed, its stronger than the tko500 and has different ratios for 1st and 5th, the tko500 is rated for 500ftlbs and the tko600 is rated for 600 and I dont think the 600 is much more expensive, couple hundred

 

G-Force Transmissions makes beefed up T-5's, if you want something you can swap in directly. Pricey though.

 

Yeah, with only $1,000 to play with your best bet is to either get another T5 or get yours fixed. You cannot powershift it with this kind of power. They will break if you powershift them with a stock motor too much. Usually 3rd gear gets wiped because the car has traction at that speed. 2nd usually gets saved becasue the tires will just break loose rather than shock load the trans. Drag slicks and clutch dump launches are also to be avoided. This will break first gear and the cluster gear.

The TKO500 is Tremec's new name for the old TKO. The TKO600 is basically an upgraded TKO with a 32 spline mainshaft (same as a Viper T56 or TH400). The TKO 500 is rated to 500 lbs/ft. and the TKO600 is rated to 600 lbs/ft. They are great 5 speeds, but you will spend $2,100 for the TKO500 and $2,200 for the TKO600 for just the trans. Some other parts need to be changed too, so plan on $3,500 for the swap.

The T56 is close to a bolt in, but is still pretty costly. They are officialy rated to 450 lbs/ft. for the '94-'97 LT1 version, which is the one I would suggest using as it simplifies the install greatly. Cost on a complete swap is going to run $2,000 - $5,000 depending on how much of the old stuff you want to reuse, what clutch/flywheel you go with, if you opt to rebuild the trans, etc.

G-Force can build a T5 to handle up to 500 lbs/ft., but the cost is going to be close to a TKO500. The benefits are that it is a bolt in trans with no other parts to swap, and the shift feel is much less notchy that the Tremec.

 

Like TKOPerformance said, your only real option for $1,000 or less is a junkyard T-5 or rebuild. I don't remember the exact price, but G-Force's kits start at about $1,500. That doesn't include labor, shipping, or the upgraded mainshaft and cluster support plate that they use to get the 500 ft.-lbs figure. Fully built, they cost about $2,400 including shipping and labor.

 

Yup, that's about the size of it. G-Force also has an upgraded case available now for $250. The 4340 mainshafts were $500 six years ago, and the gear kits were $1,100(and that doesn't include 5th gear, which was an additional $90 as I remember it). $200 for a rebuild kit with all the bearings, etc. Then there's the cluster support, the bronze shift forks, etc. It adds up in a hurry. G-Force isn't posting prices ont heir websites anymore either, which is weak IMO.