DopdBrd

iTrader: (25)

Will the LS1 heads fit on a 5.3 liter block out of a truck??? Guy here at work wants to stick them on the 5.3 so he can get the fast 90mm intake.

Beaflag VonRathburg

iTrader: (176)

Yes, they will fit. They are all interchangable. You can fit a fast 90mm intake on any cathedral port head.

sv650lex

watch out when you put the heads on. The ls1 heads have a larger combustion chamber and will lower your compression ratio.

454SuperSport

yeah, fast 90 will go on the truck heads, wouldn't do it though unless he's got some serious mods.

mullenh

iTrader: (1)

putting ls1 heads on a 5.3 is not an upgrade in performance. you would do this if you increased displacement, or if for some reason you needed to lower compression. a 5.3 head swap is an upgrade for and ls1 because it increases compression with its smaller chamber. with some good machining it will flow well too.