I'm getting an '86 IROC as a parts car, with a rebuilt 700-R4. The rebuild has virtually no miles on it. It's actually still at the tranny shop, and I'm getting the whole car if I pay the rebuild bill. I want the tranny for my '87 SC, which has an LG4, but will eventually have a H.O. 350. What are the primary differences between an '86 IROC 700-R4, and one in an '87 SC? I'm not sure exactly what, but I know that the 700-R4 was somehow improved for '87. Is an '86 bad? An IROC one has a Vette servo, whereas the SC one doesn't, correct? By next winter, I want to put in the H.O. 350, and a B&M Megashifter. Is this transmission going to hold up, or should any modifications be made?

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'87 SC 305 "Chrome Yellow"
ASCD Turbo hood
AR rims
Flowmaster cat-back
Alpine deck to 4 Polks
'81 Z-28 "Dodge Viper GTS pearl blue"
H.O. 350, TH-400 w/ B&M megashifter
Harwood LS1 hood
Z-racing rims
True Dual

 

Some of the 87's are better and have some advantages yes, but there are guys running good with 700R4's that aren't 87-92 transmissions that are built for performance also.

 

I have an 85 700r-4 in my 86 iroc and it has a shift kit and whatnot and shifts better then my iroc trans did,i am sure it will hold up whne you put in the 350,if its a fresh rebuild then you should be fine,you should have them put in the vette servo,its pretty simple to do and doesn't take long.

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www.rearman.com/camarokid.htm

If it aint a V-8 that $hit aint fast!,unless its a GN,lol!

305 tpi,700r-4 with shift kit,My mods are minimal,just a bunch of little $hit.Anyone know where to get underdrive pulleys for a v-belt set up?

 

As long as it IS the original tranny (find out) it will have better WOT shift timing than the regular units. That is about the only advantage. Will it last longer? That all depends on who did the work.

 

The main change for "Trans longevity" was the fluid pump... '83-'86 had a disc with evenly spaced vanes in the fluid pump (I think called stator? rotor? ugh..), and the pumps burned up & ran dry. For '87-up, GM added a few more vanes, and made them unevenly spaced.

Of course you can put the newer pump in an older trans, so it depends on what they did.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

Don't the IROCs come with this?

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'87 SC 305 "Chrome Yellow"
ASCD Turbo hood
AR rims
Flowmaster cat-back
Alpine deck to 4 Polks
'81 Z-28 "Dodge Viper GTS pearl blue"
H.O. 350, TH-400 w/ B&M megashifter
Harwood LS1 hood
Z-racing rims
True Dual

 

Actually the 7 Vane pump is fine. If you think about it, the more vanes, the less volume of oil it can move! The reason they changed the spacing on the vanes and went to the 10 vanes was to address a 'moan' complaint. The pump tearup can and still does happen to this day even with the 13 vane vane pumps. The problem centers around two main areas; weak pump rings and hydraulic circuit problems (Which GM finally copied from the TransGo Shift Kit to address that issue).

Many years ago I converted a '77 Monte I had from a 350 to a 700 (this was when everyone was still going the other way). After I was done with the car I took the tranny out and sold it to a guy with a Suburban that had been through 3 trannies. He went over 200K with this unit and he sold it to someone else who is stil using it! I didn't change the pump over even though I easily could have. I DID make sure that the pump clearances were tight and I put the TransGo HiRev Pump Rings Kit in to keep it alive. The reason I point this out is that the only core I could get my hands on at the time was a 1982! This was the second version of endless updates but with the right setup these trannies were just as good as any other so don't be so worried about what year it is, it's what you do with it.



[This message has been edited by transfixleo (edited May 31, 2001).]

 

Transfixleo,if i lived closer to Webster i would go to you for my trans needs,right now i just finished installing a 700r-4 in my 86 iroc,it came out of an 85 t/a,it has a shift kit in it and shifts great,but i have a leak i believe is from the pan,got any suggestions?,is there anything i can use to seal it up good,would rtv sealant be good or a gasket sealer?

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www.rearman.com/camarokid.htm

If it aint a V-8 that $hit aint fast!,unless its a GN,lol!

305 tpi,700r-4 with shift kit,16 by 9 American Racing cross laced wheels,My mods are minimal,just a bunch of little $hit.Anyone know where to get underdrive pulleys for a v-belt set up?

 

I never use anything on pan gaskets. First the pan surface needs to be flat. Often the pan bolts have pulled up around the bolt holes and that keeps the rest of the pan from sitting properly. You can just put the pan against a flat surface and tap the humps down with a hammer. I also like the FarPak gasket (they look like cardboard) but they need to be retightend once after install since they take a set. The regular Cork and Rubber pan gasket is fine too as long as the surface is dry.

That all being said, are you sure that the pan is the leak? You could have a filler pipe leak, cooling lines, Servo cover, Linkage Shaft Seal, Vent (!) or even front pump (sorry).

 

Hey transfixleo,i dropped the pan and i cleaned it all up and tapped the holes down, no more leaks just like magic. ,thanks for the help,i did use gasket sealer,is that bad?

------------------
www.rearman.com/camarokid.htm

If it aint a V-8 that $hit aint fast!,unless its a GN,lol!

305 tpi,700r-4 with shift kit,16 by 9 American Racing cross laced wheels,My mods are minimal,just a bunch of little $hit.Anyone know where to get underdrive pulleys for a v-belt set up?

 

As long as it doesn't leak, no problem!