I'm thinking of using this kit to rebuild my stepson's 83 Z28. Upgrading to moly rings, Felpro gaskets, Clevite brgs.,Speed-Pro CS1014R cam, and flattop pistons. I'm not looking to build a rocket, it's his first car, just give it a little more kick. How much will the flattops raise my compression? Does it sound like a good combo?

Forgot the link:
http://www.northernautoparts.com/Pro...uctModelId=720

 

That cam is the 204/214, nothing special about it - it should work fine.
What 305 is in this 83Z? The LG4 or the L69? The dish pistons would make it ~8.5:1 I think, and the flat tops 9.5:1 IIRC.

I'd go one step bigger to the 214/224 cam listed. You're basically just refreshing the engine, ie bearings and rings. Nothing there is going to add any power, so you'll still have the 150HP LG4 or the 190HP L69. The cam is marginal, don't expect much. I'd look at exhaust if there was any HP expectations.
Make sure to do valve seals while you're doing this, grab the positive seals by felpro (buy two sets of intake seals) and you're set.

 

Looks like you need to go with standard iron rings. If you are just using a flex hone to cross hatch the cylinders, it won't fix non-circular cylinders. Coated rings are only to be used with fresh cylinders (not out-of-round). Iron rings will wear into irregular shaped cylinders quick and seal better then the coated ones that may not seal well otherwise.

Stock heads? Then don't get crazy with the camshaft.

What is wrong with your pistons? I could not sleep at night building an unbalanced engine, unless you can match the weight of the old piston to the new, I think you are looking for trouble (complete balancing cost over $200 around here).

 

Nothing wrong with my pistons. Just hoping to gain a little with more compression and a slightly larger cam. Like I said I'm not trying to build a hot engine, just a little better than stock. If the pistons are not going to make a noticeable difference then I'll spend that money elsewhere.

As for balancing, there is nowhere around here that even does engine balancing. I know it's a good idea, but I have slept at night without balancing.

 

Ya, if it is just for a toy car, then it shouldn't be a problem (not goin for longevity) and you aren't spinning high rpms.

 

Pistons (higher compression) will make the engine snappier off the botom and a little torquier...but were not talking high performance #s here. As Sonix recommended, the 212/224 cam (the 204/214 is only a stock OE type cam) and higher comp pistons along with stock cast rings would be a good bottom end. Top it off with a Performer RPM style dual plane high rise intake with a good Q-Jet and a free flowing exhaust and you've got a nice "stock" play motor to enjoy. Balancing would be nice, but for a 4800 rpm street engine you should be okay.