I have a few questions concerning my 3.2 rebuild I am undertaking. First of all, the balancing of the new crank has got me confused. My machinist said he could balance the 3.1 internally and retain the stock 2.8 flywheel. I questioned this, but he assured me that there were ways to do this and there were some versions of the 3.1 that were internally balanced. Now this is the same guy who told me that 3.1 aluminum heads would fit the stock manifolds. Is this another guess on his part or is it really possible?

My next question is about the pistons. Are there forged pistons available for the 3.1 that don't have to be custom made? I don't want something that will break the bank, but at the same time I need pistons that will hold up under some moderate abuse. I was warned about hypereutectics. They are heavy, prone to breaking and are hardly better than their cast counterparts. I plan on shooting some nitrous through this motor someday and I definatly don't want my pistons to be the weak link.

Do I need a fuel pressure riser? I've heard of people who don't use them and some people who swear by them. What's the story?

The 88's are internally balanced and have a neutral balance flywheel. The earlier ones are externally balanced. You would need an 88 flywheel if yours isnt't an 88.

The topic of the aluminum heads not fitting the intake manifold has been discussed on numerous other threads. They wont fit because the intake port spacing is different.

My car is an 88, but I always thuoght all Fiero V6s were the same.

Hypereutectic pistons are good pistons. The way I would describe them strength-wise is that they are halfway between cast pistons and forged pistons. For a high performance street engine they hold up much better than stock cast slugs. However, if you plan on lots of hard useage, high rpm, and especially if you are going to juice them (use nitrous), then by all means find some good quality forged pistons. Laughing gas is very hard on engines, build it strong or it won't last.

Forged pistons are a tough find. I think you can get a set from JE for around $700, but that's way way too much. It's funny, the machinist discribed the hypereutectics as "slugs". I guess everything should stay together for awhile as long as I don't get one of those funcky little blue bottles. I'm not going to build this thing to rev much either. The roller valvetrain is too expensive and realistically, I'm not going to push it much past 6,000rpm anyway. He is the first person to say anything negative about the hyper pistons, of course most of his clients are people who really want their cars to rev (drag and circle track racers).

If anyone knows anything on the balancing issue please tell me. I'd like a second opinion.

I don't know a lot about this flywheel thing, but I believe you can internally balance a 3.1 crank, IF (big if) the machinist is good and knows what he's doing. It's probably cheaper and may give you more peace of mind to use a 3.1 flywheel that matches the crank instead. I'm sure a salvage yard can come up with one for you. PaUL seems pretty knowledgable, maybe he's right about that 1988 flywheel. Do some more checking around.

You could have the pre '87 flywheel balanced to nuetral,or get a late model flywheel for les money than the work.
If you're going to lighten the flywheel,you could use the early one and have it balanced to nuetral after,with the clutch mounted,and indexed for correct re-assembly.That's what I'd do for any performance/high revving motor.