How much more hp will this make???? And what is the cost?

Do I got to bore my cylinders on the rebuild if there is no cylinder sleeve damage? Can I just threw in upgraded pistons and rings?

Any help appreciated

 

Keeping stock stroke and boring it out .030 will give you a 355.

The real power is in the heads and cam and the gain from the few extra cubes is somewhat negligible.

Unless the rebuild is absolutely necessary you might want to look at spending the money on your valvetrain, heads and cam.

 

I already got ported and polished LT1 heads with bigger valves amd a cc306. Could I just throw in new pistons and rings without boring? The block has 88k mi with no cylinder damage

 

Yup....as long as the cylinder walls are fine...no scoring, etc.

 

I can take your question 2 ways..
Hopefully you aren't asking if you can 'upgrade' to .030 over pistons without boring?[if you are... NO you can't]
But yes, you can change to standard size pistons without boring..[you can hone and rering the stock pistons, also, if they spec out]
Like said a .030 over will make negligible power..
Put your $$ in heads and a cam, etc..