Hi everybody! I'm new to this board, so I'll start here. I have an 87 iroc-z, with a 305 TPI. I believe it has a 700r4 tranny. (It's an automatic). And I have no idea what the rear-end is. It used to run fine, until I took a long trip awhile back, and ran it up to 120 (for the first time, since I've owned it) Well, I did something to the motor, and it's time to get rid of it, and get some horsepower!!

Now, I don't have much time, and am gonna have a good friend do this swap (I travel a lot, and am not around as much). But, I would like to put in a small block with around 450-500 horsepower (could I get more, staying with just gas) I don't wanna go nitrous, and I don't wanna go turbo,or supercharge. Just wanna get as much horsepower from small-block that I can.
I also am gonna get a built up 700r4 tranny, and a bolt-in rear-end. The object will be to have a street-legal sleeper, that will run into the low 10's, maybe 9's? And to beat all of these guys around here with there little mustangs, and the growing number of rice burner (I wanna be a race car driver) groups that I have popping up all over the place............

The objective is to leave the TPI and stuff in place, just the hookups, and not to make any MAJOR modifications, so that when I get tired of this (Not likely for a long time)I will have rebuilt the original 305 TPI, and can put it all back stock. But for now, I would appreciate any info, or links to where I can get the needed information on how to do this swap. Like I said, wanna stay small block (I have a small block 400 sitting in storage to build up, or maybe just get a 383 stroker, or a crate zz motor)

I have a lot of questions, like, will I be able to use the computer, if I go to a carburated engine. And, what exactly does the computer in the car control? I know the speedometer comes off the tranny, but what about the tach? That hooks up to the motor, to the distributor somewhere, doesn't it? Also, just spent a lot of money last summer getting a new A/C system on this, and would like to retain this. Will I need any special pulleys to make a 350 or 400 block fit? Will I have any problems with my power steering gearbox in the way? Will my radiator be able to handle a 4-500 horsepower motor? It's all original, and the radiator has two electric fans on it, which I got working last summer, when I had the A/C done. Lots more questions, but this is probably long enough for now.

Thanks in advance, Lloyd

 

What about sub-frame connectors? Where is a good place to get them?

How about "true" dual exhaust? Will it be possible? If not, where is a good place to get a performance, bolt-on exhaust?

I was gonna have a local hot-rod shop put in a 9" ford rearend, at the tune of $2,500.... But, my friend showed me in a hot-rod magazine, of a place that has bolt-in rear-ends!! But, I'm wondering if I will be able to get the same performance from one of these units, that I would from a 9" ford......

More to come, I'm sure......

 

Welcome aboard.

Well, I think you're at the best place for information. I'll give my opinion, then anyone else that wants can throw darts at it.

I think your goal of 450-500 hp is a little lofty. But, you can meet your goal of a fast sleeper (perhaps in the low 12's).

Use the 400 you have now. Get it checked over thoroughly, and put some good stuff in it: forged flat-top pistons, 5.7" rods (meaning get pistons for that length rod). You'll probably bore it .030" over, so that will give you a 406. If you really want to go nuts, get a steel crank (like Scat) for it, but the factory piece should be okay if checked out and turned. Really, really nuts would be to stroke it even more than 3.75" with that aftermarket crank.

Heads, don't skimp there. You really need good heads to make good power. At the very least, World Sportsman II's, but AFR's would be even better.

Pick the cam to get you into the power range you want, then pick intake and carb accordingly. A Performer RPM with 8xx CFM Demon sounds sweet from this distance.

A couple of issues that will have to be addressed are externally balanced harmonic damper and flexplate - unless while going nuts you get an internally balanced crank. If externally balanced, you'll probably need a ministarter.

But, everything else should bolt up. If you go with true dual exhaust, then definately get long-tube headers, preferably 1-3/4" primaries.

I doubt it would cost you any more to put such an engine together than a ZZ crate engine would run.

The 12-bolt for F-bodies makes more sense to me than any 9". But, that's just to keep your GM car all GM. Definately need that built TH700 (talk to Dana at ProBuilt). For subframe connectors, see our sponsor's button above - Spohn.

With this combo, you'll have a mild-mannered daily driver that will surprise a few people when asked. You'll probably need some sticky tires on the track to get it hooked up, though.

Good luck! Keep us informed.

 

Well, after posting my original message, THEN I discovered all of these motor swap posts....duh! Well, I haven't started anything yet, but after reading a bit, I'm thinking about a 502ci now. I just want to much power for a small block. A LONG time ago, I put a 350 into a chevy monza, bored .30 over, flat tops, with a mild cam, but ran out of moola, and had the original rear-end, which couldn't get enough traction, and didn't finish the top-end, via the original hei distributor, no msd box, e.t.c.

Years later, I wish I still had that car, but now I have the iroc! Yeah, I think I'll just hold on to this 400, and go a little at a time, and stuff a big block in there....... I thought I could have it all done quick (while I have the money to do it right), but now think I will just take my time, and do it one step at a time.

I appreciate the info on building up the 400 though.....
The real question is about the TPI stuff though, haven't ever fooled with it, and don't know much about it, don't know how it's hooked up to the ecm, or if I'll need any of it.

Like I said, am definately going carburated, and it looks like a 502 now......