littleredcorvette88

The time has come....my transmission is slipping like crazy and just revs out.

What have you guys done for upgraded transmissions? I have roughly 425 whp right now and possibly more in the future so I would want it to be able to support more power than needed. What are my options? its currently an automatic.

I was thinking either rebuilt a stronger automatic to handle the power or go 6 speed? If i did go 6 speed what are the factory 6 speed transmissions rated for? Would I need to rebuild one of those? Whats involved in converting an automatic over to a 6 speed? Is it worth it?

Or.............am I better off just rebuilding my automatic transmission?

I would rather not spend a ton of money if I don't have to and I have a few local people near me that could rebuild my automatic trans. at a decent price.

The car is a 91 with a 396ci L98 motor

thanks

SeeFourSix

IMO, you're better off $$$ wise rebuilding your auto to handle the power unless you have a full donor car with the ZF 6 speed.

l98tpi

I would recommend to rebuild and beef up your auto and if you are dependent on precise shifts, then go with the full manual valve body. I mostly autox and precise and instant shifts are a must. My trans was built by RPM Transmissions and is one of the best upgrades I have done.

383vett

So far this has been my cure for transmission blowups.

93 ragtop

where do you live? I have a friend who has done mine and it has held up well. His shop is in MD And he is very reasonable.

C409

..... For what its worth ... I build my own trannies and get a discount on parts ... I recently built a 4L60E to handle 550hp and spent almost $1000 on internal performance rebuild parts and that did NOT include the labor , a torque converter or the electrical portion of the valve body ... i.e. : switches and solenoids ... food for thought for when your buddy tells you he can rebuild your trans for $600 ..............

littleredcorvette88

Hmmmm yea still trying to figure it out .....located in boston

littleredcorvette88

Where did you get the rebuild kit and what exactly would i need for parts to rebuilt the trans to handle 600-700hp ....I would rather overbuild it then under-build it and may run nitrous in the future.... I have a guy to rebuild it but I just want to get the parts together before I give him the trans. I'm sure he could tell me what to get but I haven't talked to him yet.

Thanks

Kevin Woods

Well.....you can go with a budget rebuild.....and end up replacing the tranny again in a year or twe.

Or.....you can do as others have suggested and get a built tranny.

In the B-body world, many have gone with Pro-Built Transmissions with great success....they will ship from California to Boston.....

http://www.700r4l60e.com/

Best of luck!

KW

C409

..... The bulk of the parts were from Dacco Detroit ... they have warehouses here and there including one in Tampa ... some hard parts I buy from the local Chevrolet dealer ... like the reverse input drum and the rear 5-pinion planetary ... every builder has his favorite frictions ... I use Alto Red Eagles and Kolene steels throughout and the red eagle band ... Superior billet servos for 2nd and 4th gears ... the Beast reaction shell ... watch out for imitations ... I replace both sprags ... and I use the Transgo 700-2-3 shift kit ... and always replace the bushings ... use a no yo-yo kit ... and the upgraded clutch piston return springs ..... for 600-700hp you might want to consider the input drum reinforcement , by Sonnax I think ... and 300M input and output shafts ... and the forward 5 pinion planet ....... I'm sure I forgot a few things , but this'll get you started ........... ..........

aklim

I had and have a Rossler trans myself. Lingenfenter told me that my stock rebuild was toast after he tuned the 383 motor for me. Gave it about 9 months. Within 3 it was done. Got a Rossler rebuild and it lasted for 3 and a half years, I believe. This was with me hitting it several times a day all year long unless there was snow on the ground. Got it rebuilt with "The Beast" sun shell gear and several other upgrades and it is still holding because I am not driving it as much although I am making more power with the better AFR heads and HSR and cam and tuning from Hitech Motorsport.

littleredcorvette88

Now the other option would be to convert to 6 speed....what can a stock 6speed trans for a 91 hold for power and what would I need to upgrade on this trans if I wanted to support the power my car is making?.....sorry not to familiar with transmissions...its all new to me

Matatk

Best advice here. I went the budget route with my first rebuild and my 400+ hp stroker. Bad idea. Lasted maybe 8,000 miles before I broke the torque converter, fried the clutches, and broke the rear planetary.

I ordered my rebuild kit from Dana at probuilt - great guy to deal with. I spent around $800 for that, another couple hundred in hard parts, $500 for a PeteK 9.5 stall converter, and other misc costs.

My builder commented on how high quality and comprehensive Dana's rebuild kit was.

RPM also has a very good reputation, as well.

I think it's better to buy it all predone as a package so you know everything is inspected and built right by a company that specializes in the 700r4.

Learn from my mistake - there is no such thing as a "budget" trans with a modified motor. Do it right the first time. Don't forget the converter, either.

Matthew

Strick

I had a tranny built by Mad Dog Transmissions in Atlanta. Look at his site and pick what you need. They specialize in 4L60E's.

aklim

I wish people would stop calling a "budget" something. It is an "expensive" something in reality. Think about it. How much does a "budget" build cost in the long run? How much time and money does it cost to do it right the first time as opposed to someone telling themselves "I don't need a racing (insert part here), IOW low cost part."? From my experience, it always costs more to do it right the 2nd time as opposed to the first time. Things are cheap for a reason. They skimped on this, that and the other to the the price the sucker wants to pay. Only, by the time the sucker finds out, well, they moved on to the next sucker. Now if I cannot afford something done right to the Vette, I keep it till I can afford it.

Now, if I were to sell a car, you bet I'd go for the "budget" build and let the next idiot deal with the problem after the 5-50 warranty. 5 seconds or 50 feet, whichever comes first.

Cliff Harris

I have a Dana Wilkes Pro-Built kit in my 700r4. He has been racing a Firebird with a 700r4 for many years and knows what holds up and what breaks. He picks and chooses from a variety of sources for the parts in his kits.

My experience is that he is a little flaky. Hard to get ahold of and doesn't always answer emails. He told me he is retired from building transmissions and just sells the kits now. He works out of his house and doesn't always have all the bits and pieces "in stock", so you might have to wait a while to get your kit. He's one of the most knowledgeable trans builders around and it's worth a little effort on your part to get one of his kits.