lasher_350

Okay, okay, I know all 350 bores are (non bored) 4"....my question is: Will pistons for an '83 block work in an '87 & up block? I have a set of pistons and want to get a newer 350 block that has a roller cam setup in it to rebuild for my bird. I don't know if oil ring groove positions factor in or not. Somebody please make this simple for me! Thanks!

ede

should be the same, i'd be careful using used pistons unless i knew their history.

lasher_350

Oh, no, they aren't used, they are brand new. I bought them way back when but never used them (saving money by not paying for them to be pressed on the rods, silly me). They are still in their box, the only drawback being is that they are standard bore, not oversize. I'll have to find a very decent block to use them. So just as I thought, they'll work. The thing that was throwing me was just browsing through Jegs and seeing different piston groove dimensions. Thanks for backing me up, now I won't worry about using them! Great!!!

Damon

You're good to go. The changes they made were for different compression ratios, emissions-type designs with beveled edges, and updates as the piston material became more high tech requiring redesigns and other reasons that won't matter to you. You can drop them right in on a new motor no problem.

flyin89

iTrader: (7)

I would just take the old pistons clean them real good and weigh them after being pressed off. If the new ones are lighter then there should be no probs. I've seen a 96 vortec block disassembled and the pistons have a very small skirt no way would I try to put reg pistons on that rotating assembly without balancing it.

lasher_350

Okay, great info. I don't think I'm going to go with the newer Vortec block and all, I'm thinking like an 88 or so, just the new style with the 1 piece rear main and the roller cam setup. I do plan on putting some Vortec heads on it though, and an intake to match. I'm not looking for all out asphalt burning power, just a pretty darn quick little daily driver. But I will weigh the pistons prior to and balance the whole rotating assembly before I run it. Is it also true that you can bore out the cylinders .010 over and run bigger rings? Is that wise, or should I, if worse comes to worse and I can't use my standard bore pistons, just go ahead and go .030 over and buy pistons to match better?

RB83L69

You don't have to re-balance a rotating assembly when you change pistons. They're reciprocating mass, not rotating mass; so as long as all 8 are the same mass, it doesn't matter what the mass is.

As far as fit, all 350 pistons are the same. (stock configuration, that is of course). They have the same diameter, same compression height, and same pin bore diameter; and the same clearance on their bottom surface to the crankshaft journals and counterweights since those are all the same size.

lasher_350

Sweet. Everybody, thanks. Now I'm going to start looking for a Salvage Yard engine. Awesome.

Randy82WS7

how do you weight match rods and pistons ? remove some metal material from the heaviesat ones to make them match lightest one ?

RB83L69

Yup, that's about it....