Bottom End.
 

Hey i heard people say to build up the bottom end of the motor..Is it possible if u build up the bottom end boost more psi's? I got a few questions Rebuilding my engine how much is the estimate of the cost? while rebuildin what are some add ons mods I could add so they wont charge me later on in the future? Whats the biggest gears i could go if supercharge, i got a 00 gt automatic.i know 4.10's auto but whats the most i could put on gears and not mess up.. 4.30s? will the stock motor be able to handle more than 400hp if build up?....

WHen you rebuild the motor you change the pistons,connection rods, and sometimes crank with strong peice that can take more power and compression.
So when you beef up the bottom end you can run more Nitrous,PSI,compression.

As for gears it depends on the power you are making and if its a street car or not. If your pushing 500hp 4.10 gears would not be the way to go on a street car with all the wheel spin you would get.

gears should be selected based on your cars power curve and the other drivetrain components configuration. That said, 4.10's may even be a bit much with >400rwhp. That's a lot of gitty-up. You could drop down to 3.55's at that point but you'll have to spend 10K minimum to do a good job.

Buy a built 8.5:1 short block from one of the zillions of assemblers like DSS, CHP, etc... It'll save you time and money and it'll hold oodles of power. You can use your stock heads or buy some already done up for even more grunt. Patriot, VT, etc... can hook you up there.

Use ARP bolts and studs, and stock FRPP head gaskets. You'll then be ready for pretty much any kind of boost you want to slap down.