ok hears my problem i have a 95 z28 that im going to make my sundday driver and drag racer the motor has 130000+ on it. i have done some mods to it cam minor head work etc. hears my delema i want to go with more ci i want have 400ci and turn it to 7500 rpm i know the stock bottom end on a lt1 cant handle much past 6000 for a sistaned time what should i do to reinforce it or would it be better to go with an aftermarkit block? what should i look for in a head i know i need a head that is going to be able to flow a lot of air i just dont know if to much cc is a bad thing. i allso want to run a nos set up of 150 shot then 275 shot. i do not have a clue as to what cam i should use i got a comp in her rate now .510 int. .540 exe. i think 290 dur on bouth and lsa 112. almost brand new if that will work then ill use it. there is probly a tone of other stuff i need also so any help would be great.

 

The largest you really want to go would probally be 396 C.I. You can do this with a 3.85" stroke crank and I think a 4.060" bore. You need a forged crank, pistons, and some good forged H-beam rods. As far as your cam, the cam you have will not be near large enough. I would talk to Lloyd Elliot @ www.eportworks.com about the head/cam kit, you will probally want a stage 3 setup and this guy knows his stuff. I would also make sure and spend the extra money to get 4-bolt mains. This can be done by purchaseing the mains and having the block machined for them. Hope I helped and goodluck.

 

does the lt1 block have the same water pasages as an aftermarket block?

 

Hard to know where to start, but I'd forget the 7,500rpm goal for a couple of reasons. The stock LT1 intake will NOT support 7,500rpm, especially on a big inch motor. So, a very expensive custom intake will be needed. Extensive head work will also be needed for the same reason. Also, an engine that sees street miles, rather than track use, will require very expensive valve train components to last at that kind of rpm. The factory PCM (computer) will not work above 7,000rpm, and so on.

As far as displacement goes, if you use the "search" function you will see a lot of discussion about 383 v. 306 for the LT1. Larger than 396 HAS been done, but isn't practical.

Rich

 

I'm sure Rich meant to type "383 vs. 396".....

396 (actually 395.42ci) = 3.875" stroke and a 4.030" bore.

I suspect that " i think 290 dur on bouth and lsa 112" is the "advertised" duration. You need to know the duration at 0.050" lift, since not all cam manufacturers use the same method to determine "advertised" duration.

For 7,500rpm you are talking a very high $$$$ solid roller camshaft/valve train, while I suspect your current cam is a hydraulic roller.