im wanting to build up my 283 so im wondering if it would be possible to put ls1 heads on it and another thing how much hp do you guys think this motor can take im hoping about 500 but im thinking that not going to happen any help will be appreciated.

Can't tell you if the heads will fit as I only work with the old stuff. As far as 500 hp, I sure hope you have a big wallet as it can be done but if you cannot manufacture what you will need to do it then it will cost you a fortune.

You can not do that. The block and intake system for a ls1 is totally different. If you were to build an LS1 motor, with the right parts, 500 hp is not a problem.

Adam