johnLs1camaro

iTrader: (28)

I have a 03 lq4, i was wondering which heads i should go with, I have some 99 heads that are lightly ported and milled(nothing special) or should i keep the 317 heads on it? I am running a ms4 cam in it. I was also wondering if going with a ported ls6 pump on this will be fine. Will my ls1 wiring harness work with this engine or should i switch anything up? thanks for any help

Pocket

iTrader: (22)

Your stock harness will work fine, no changes. Physical dimensions of a GEN III iron truck block are identical to that of a LS1. Just dont forget to drill the alt boss before putting it in the car. Much easier while it's out

johnLs1camaro

iTrader: (28)

what do you mean about the alt?

sman

iTrader: (4)

You have to drill and tap a hole in the front of the block for the alt. Ive run a 5.3 lm7 and a 6.0 lq9, both have required it.

johnLs1camaro

iTrader: (28)

damn, did not know that.. thanks for that heads up.

bww3588

iTrader: (49)

leave the 317's and mill them down. they are exactly like 243's except with larger combustion chambers.

bww3588

iTrader: (49)

you dont have to drill the alternator hole, it will work with 2 bolts, but its a good idea if you remember.

-Q-

iTrader: (10)

I didn't drill and tap the boss for the alternator either, and I've had no issues. 2 out of the 3 bolts hold just fine.

Pocket

iTrader: (22)

YES you do

The main bracket has 3 bolts on a alum block. Iron blocks are completely missing the top left boss, so you're down to 2 from the start. The bottom is drilled/tapped, the top right is present but not drilled. You CANNOT mount an alt using one bolt down low and the rear brace and expect any sort of reliable service from it