69chvelle

iTrader: (11)

Ok, I've been searching and reading, but no conclusive answer:

I've heard people say that the 98 heads are perimeter bolt, but some of my searching suggests that maybe just the valve cover is perimeter bolt. Basically what I want to know is will every LS1 head bolt onto a 98 block, including the truck heads?

thunderstruck

iTrader: (15)

you are correct about both

69chvelle

iTrader: (11)

So is that a yes, all heads will fit a 98 block?

69chvelle

iTrader: (11)

This is from JRP's newbie tech from the sticky above. It says all Gen III heads are interchangable, but also says that the 97-98 heads are perimeter bolt. So that means the 98 block has provisions for other head bolt holes? Correct?



Head Casting Info

ALL Gen III heads are interchangable.


Here is a list of a few casting #'s:

933 97 aluminum perimeter bolt 5.7
806 97-98 aluminum perimeter bolt 5.7
853 99-00 aluminum center bolt 5.7
241 01-03 aluminum center bolt 5.7 (some late MY00 cars got 241 castings)
243 LS6 aluminum center bolt 5.7
862 and 706 99 and up 4.8-5.3 truck heads
873 99-00 LQ4 6.0 iron center bolt heads
317 01 and up LQ4 6.0 aluminum center bolt heads
035 02 and up LQ9 6.0 aluminum center bolt heads

thunderstruck

iTrader: (15)

the bolt pattern is the same regardless if the valve cover bolt pattern is perimeter or centerbolt, does that help ?

blu98ta

iTrader: (4)

The center bolt or perimeter bolt refers to the Valve cover bolt pattern. All the heads have the same head to block bolt pattern.

69chvelle

iTrader: (11)

Thank you, that clears it up.