mscd1981

To spare the boring parts i'll tell you that after recently selling an old car of mine, my "crazy/diesel truck/ East Texas Cousins were sad that we didn't have any more cars to work on/ play with, so I found us a '87 IROC Z that is complete, other than the transmission. The good/bad part is it is fully disassembled. The guy I got it from was going to paint it, but never did. The body/all glass and interior are is really good shape. It does have a 305 in it "sitting next to it on the floor" and no transmission. My first question is what kind of transmission should I look for in hopes of eventually putting a bigger engine in it? 700R4 etc.... I didn't want to clutter up the message boards, but thought this would be a good place to start posting. I'm not wanting to pour 1000's of $ into this but wanted something fun for my cousins to help with, instead of out chasing girls, or getting into trouble. With that said, no I'm not looking to go dirt cheap on parts either. Any info on things to watch for on the journey we are about to embark on would be nice, although I've been keeping my nose stuffed in this web site and it helps a lot. Thanks in advance for all the helpful posts out there. Newb here.

dabomb6608

iTrader: (3)

If your wanting automatic then the original transmission would be the 700R4. Which should handle any motor your planning on in the future.

91 Droptop

If you stay stock than yes a 700 R4 will hold up, if you go over say 350HP your R4 will die a slow death. I have a B&M in mine, I will see how it handles the new motor and super charger. You can rebuild the R4 to handle high HP, but it will cost a few hundred extra, good find on the car keep us posted on the build.

okfoz

There are things you can do to make a 700R4 (4L60) tougher. You will spend some money on it. Most Trans guys just rebuild, but really do not know the internals how to make them better and stronger. Some guys know their stuff, but finding one of those is kinda hard.


John

l_dis_travlr

By "really good shape" do you mean boxed up separately somewhere,
cause all I see is bare naked panels on the inside.
But it all looks straight & probably rust free, which will be a good
platform to start with.

How much engine are you wanting to end up w/?
I have a fresh T5 & bell-housing available. Go check out the
Transmission forum, for very good discussions/analysis of the T5's.
PM if interested.

Welcome to the third-gen family, and thanks for helping keep
the breed alive. Start a restoration post, so we can all
ooh-ahh, and lie about how well you're doing and that we wish
we could do the same.

fbodylove84

If I want a cheap trick to ur 700r4 use the corvette servo stiffens shifts and helps improve the life of the transmissiom

okfoz

Remember that there is more to a Corvette Trans than just the servo and not all 700R4/4L60's are the same. The later trans were better, but internally there were differences to where if you mate a L03 Trans to a L98, and just changed the servo, your trans will not last, you have to change some internal parts to make it stronger...

John

fbodylove84

After 86 is when the 700r4 changed their spline count and are the stronger transmission I have a 355 in mine and I ate up 700r4s like can't switched to a 400 and havnt had a prob no overdrive but they won't break

TTOP350

iTrader: (8)

Talk to Dana @ probuilt to have a 700R4 built.

Davejs

I just talked to the guys at PACT Transmission aka Raptor Transmissions to get a parts quote from them. Parts to rebuild my transmission to a level 3 that will hold the 450hp 465tq engine was reasonable I thought compared to others. Put it this way I had a local shop bid low and charge $1500 for trans and lame convert for a TH350.
http://www.transmissioncenter.net/