Ok im looking for some imput  i have a 88 iroc that iv recently started on  and every one keeps telling me to ditch the 700r4  and the tpi unit but i like the overdrive and cant aford add on unit the tpi is more of a i want to be different thing since no one around here ever uses them they always toss them it seems before i can get there to retrive some parts so far i did a swap of the blocks from a 305 to a 76 corvette 350 and added a holley fuel pump high press. in tank unit and a shift kit  

That 700-R4 is plenty fine for what you have...a lot of it is hype.  The 700-R4 is a capable transmission...and if you do a few things to it...it'll hold up to quite a bit of power.

The TPI system is a pretty good system...and you can make power with it...but pretty much only at a low rpm (I know they'll go to 5500...and maybe 6000...but pretty much you want to keep it low).  Thats not such a bad thing for a street car.  You'll want bigger runners and a higher flowing base...but the system itself is fine.

I really wouldn't worry about what other people say.  A TPI can make plenty of power for a street car and the 700-R4 can handle what you are going to throw at it (if built right, they'll handle 800 HP).  So go with what you want.  Sounds like a nice combo...kinda familiar too.  I've got an 88 IROC...but mine still has the 305 (really wasn't worth putting the money into that...such a waste).

Anyway, good luck...and have fun.

thanks for the imput...... another thing I was thinking about was a 3.75 stroke crank but it would have to a cast iron one because i cant afford a forged one since im still in high  school would  that be worth the money compared to the power i would gain.........

another thing is my dad has a set of dubble hump heads with 2.02in. and 1.65ex. he said they wer saved down 30 thous., had a 3 angle valve job and were ported.  Would the tpi unit when shaved to match fit or would the bolt holes be wrong?

The larger crank would be a good upgrade...but remember you also have to replace the pistons when you do that...and get the thing balanced...I also think you have to have some clearance grinding done to the block...but don't quote me on that.  Usually cast cranks aren't recommended for high performance builds...but as long as you are not spinning it too high or hitting it with nitrous shots, it should be ok for what you are doing.  Once you start doing the machine work for that stroker, you're going to run into some significant costs.  Car Craft did an article that covered the best way to build up a TPI motor.  Its in the tech articles on this site.  I don't think the stock intake or exhaust is going to support bigger cubes without at least a little bit of work.  Put on bigger runners, a better intake base, maybe a set of headers, and it aughta handle the bigger cubes just fine...with a reprogramming of the computer...and a bigger cam...and larger injectors.

I'm not sure about the heads...I think they'll work with the tpi unit, but I know that there were some head changes made in the 80's...and don't know exactly what they were.  I'm pretty sure it was just switching to a centerbolt valve cover...but you'll want to look into that a bit closer first.  If they are already ported, and have been gone through well (not a cheap port job with a questionable machinist) then they will be worth it...again...if they will bolt up.

Good luck...

I have a 700r4 behind a street performance built 350 making more power in a heavier car. Installing a shift kit, and adding a trans cooler and a lock-up kit are all really good ideas and will improve the trans' life-span.

 I love the short first gear at lights, and the overdrive is invaluable on the highway. The lock up will help on the highway as well, but it will also keep the trans happier and cooler on long hauls.

i think the heads you're describing are for the traditional small block. Is your intake/induction designed for vortec style heads? If your stock engine has vortec style (center bolt valve cover) heads, they match up to the intake differently than traditional SBC heads. Also a stock vortec head will flow better than old style stock heads every time.

Also keep the TPI for convenience. And be sure to wave when you cruise by the rest of us, standing in our driveways tuning our carbs.

do you kmow what the differences are between the traditional style and center bolt stlye  bolt holes are?  Could my later style be redrilled to fit or am i better off finding an earlier style TPI base manifold  

To be honest, I'm not really sure about redrilling the intake. i'm under the impression that the intake ports do not match up. Also (dont quote me on this) I believe the angle of the intake face of the heads is different. When vortec style heads are referred to as "center bolt" it describes the bolt pattern of the valve covers, not the intake.

most guys i know that build street SBCs switch TO vortec for cheap power i am not aware of anyone i run with that has switched away from the vortecs,except to go to high end aftermarket aluminum heads, or for racing (heavily ported etc).

Vortec heads and centerbolt heads are completely different.  There are standard port heads that were available with the centerbolt valve covers.  I don't know if the bolt pattern changed for the cylinder heads when they changed the bolt pattern on the valve covers.  I do know that the vortec heads will not work with a factory TPI unit.  I'm 95% sure that the standard valvecover bolt pattern will work with any TPI unit, but am not completely sure on that.  No TPI car originally had vortec heads.  You can get vortec heads for your car, but you will have to get a new intake to match it.