exaust for a zz383

[uselessgrant]

I want to run a zz383 crate in my 16ft cheetah but according to gmpp fast burn aluminum heads need Lt1/Lt4 exhaust flange headers. What is the difference and does anybody make logs for these heads?

[uselessgrant]

i am referencing my 2001 gmpp catalog.. unless they have changed them lately it says use felpro gasket no.1407. Later in the paragraph under technical notes it also says exaust headers w lt1/lt4 flanges are required:confused: