I just finished one motor, but that one has to go into my truck. And I'm getting ready to begin on a fresh rebuild for my Camaro, using the 4" bore roller block that I removed from my truck.
My car is an 85 IROC and it originally came with a TPI system which I intend to keep at least til I've passed smog. This is for a CA car BTW, so the more original it is at the time of testing, the easier it will be to pass.
The heads I'll be using are the heads off the car's original 305, reworked with some 1.94 valves, and porting of course. And the block has the pass side dipstick so externally it will be close to identical to the LB9 that was in there.
Internally however, my plan is to use a LJ 3.25" stroke rotating assy (with a 2pc rear seal adapter) which I'd like to use simply because I have it and it's paid for. The pistons are some flattop hypers. And the cam is an L98 hyd roller.
The best thing I could hope for would be that the car would pass smog with that combo and the stock iron exh manifolds and the stock chip. Because I don't have any experience burning chips at all, at this point.
Then after that, I'd have 2 years to do more mods and learn about prom tuning before my next test.

I'm just looking for some feedback on this idea. I'm planning also on getting a new set of 24# injectors and an AFPR.
Can you guys give me any ideas on how this combo might work with the factory chip?

Thanks

 

Or would a 350 with the mods listed above work with the factory LB9 chip?

 

Either plan would work.

Most would say not to give up the extra displacement of the 3.48" stroke. Can't say I have a good arguement to the contrary.

The MAF TPI is more forgiving with respect to displacement changes. The '85 isn't a very good place to start with PROM tuning, but the later MAF's would be fine. You're just flow limited, that's all. Shouldn't be a problem with what you've got planned.

 

what five7 said, i wouldn't give up 25 CI of displacement

 

Thanks for the replies guys.

It's not so much a question about displacement as much as it's about getting the car running reliably and legally as cost effectively as possible. I have a good quality 327 rotating assy that's balanced and begging to put into a fresh block.
I can either use that, or spend another $1000 on one of similar quality with a longer stroke.
I think I'll go for the stroker later. Because my hands are already going to be full and my wallet empty, with getting this car legally transferred to my name.
The car I have is a nice looking 85 IROC with a rod knock. I got it from a friend who got it from a guy who got it from the last registered owner in '98 before he moved to another state.
The paperwork for this car is going to be a HUGE headache, and I need to do all I can to keep the whole project as simple as possible.

Another option I'm considering is just to repair the knock in the factory 305 if possible, and have it smog tested in stock condition. If my 327 with the factory prom tuning would not pass smog, then just freshening up the 305 would actually be the simplest approach. But then the thing is, I'd want to swap it ASAP.
So why not use a better engine to begin with, if it'll work.

What is it about the '85 MAF system that's difficult to work with?

 

This is about my 12th attempt to reply, see if it works this time...

Don't bother fixing the rod knock on the 305. Putting the 3.25" rotating assy in the 350 block would make more sense. You shouldn't have any problem with smog assuming you keep the cam reasonable.

Check on the TPI forum, but from what I've heard, the '85 ECM/PROM isn't very modification friendly. It should handle the displacement increase okay because it's MAF, but if you want to "improve" the tables, it doesn't do that part well.

But, don't take my word for it.

 

Excellent... I'll proceed on that course then, and search the TPI forum.
For smog an L98 cam ought to be as reasonable as I could get.

Thanks