I think the lengths are 4.90 and 4.95 but not %100 sure.

EQs will make about %3-%5 more power OOTB and have hardened ex seat inserts. They can also make more max power after porting.

Clearwatercylinderhead on flea-bay is the cheapest I have found. They sell bare ones, they sell assembled like stock, one like stock but with LA intake bolt holes, and one with 2.02 valves and good springs and retainers. I think they call them iron rams and heavy dutys. I think there store name is HeadsByCCH I have bought stuff from them and they do real good getting it shipped fast and not mixin up the orders or anything.