Newbie with a few questions

[gp537]

I have a 95 Grand Prix with the 3100. I was wondering if anyone knew what is the most and safest amount to bore out the engine? Also, I was considering doing the 3400 top end swap. Where is a good place to find all the parts that I need? What kind of horsepower gains would I see if I did the following mods:

3400 P&P Upper and Lower Intake
3400 P&P Throttlebody
3400 P&P Heads with 3 angle valve job and bigger valves
New Fuel Pressue Regulator
Bigger Injectors with a new ECU

Any help would be great. Thanks.

-Marc

[robby1870]

safe over bore is like .060. I think thats what GM says is safe

[donk_316]

My opinion is the gains from all that 'P&P' will be minor compared to the gains from the 3400 swap. If it makes you feel better you can knock off all the casting flash and 'port/gasket match' till your happy. Just a side note. Many tests have been done on bigger engines and it shows that a "gasket match' doesnt do anything noticable. Cant just open up the port openings without opening the whole port if you want to see anything.

Use the 3400 injectors. I wouldnt screw with anything past the 3400 specs cause your only pushing as much fuel and air as a 3400 top end will allow. When you start playing with Cams, then increase fuel and tweak your ecm. but this is just my opinion.

[geoffinbc]

Yup I agree just do a 3400 swap. Everyting will pretty much be a direct swap.