mikesfastss

whats the best way to find out the year of my ls1 all aluminum engine(is in a capri that i bought that way) . thanks mike

slayerized6

iTrader: (12)

check the casting number on the heads (unless there aftermarket heads)

F-Body_Kustoms

if the valve coverers have the center bolts then its a 99+, if there arount the out side of the cover its a 98. but the 5.3 came alu. also so it might be a 327

mikesfastss

ok cool the valve covers are center bolts and the block says its a 5.7 and head says 243

82cetuner

iTrader: (9)

the heads are from a ls6, are you positive this is not a ls6 motor? get the casting off the engine block. you either have a ls1 that someone threw ls6 heads on or you have a ls6.

P.S. ls6 blocks tend to look very shiny.

DCsLS1

wrong 2001-2002 ls1's came with 243's (ls6 heads). it is most likley 2001-2002 or an ls6 but there is very little difference in an ls1 and a ls6.

eseibel67

iTrader: (10)

^ 01-02 LS1's came with 241 heads.

Good news is that the 243's are even better.

DCsLS1

^^yea thats what i meant i think 243's are ls2 heads, i got the numbers confused

SOMbitch

iTrader: (8)

Vettes had the LS6's (243's) in them in 01-02.....

82cetuner

iTrader: (9)

not sure where you are getting your info from or maybe you are confused.

243 heads are trictly LS6 heads only and is what makes a LS6 have 10.5 compression compared to LS1s 10.1 they did not come from the factory on any other type of engine.

Ls1 engines came with 241 heads and the earlier ls1s had 799 which is just a early verson of 241s heads I THINK but dont quote me on that one.

He really needs to check the casting on the engine to find out what he has, and even then he cannot be totally sure because if it was a 02 ls1 that happend to be a ls6 block that someone threw ls6 heads on then he will never fully know for sure.

Either way he has LS6 heads so he is a little higher than stock LS1 HP.

starting in 02 ls1s were getting ls6 blocks just because they needed to use them up, there were no other changes and hp was no different.

in 01 all LS1s got the LS6 intake but the camshaft was less aggressive and HP stayed the same.

This is why putting a LS6 intake on a 2000 and earlier ls1 will give a nice little pefromance boost because the camshaft was bigger from stock.

DCsLS1

i dont know man i have my numbers all fucked up but here is the differences in ls6 ad ls1 heads

Stock LS6 Heads
Chamber 64.45 cc
Intake 210 cc
Exhaust 75 cc
Valve Diameter Intake 2.00"
Valve Diameter Exhaust 1.55"
Part Number 12564243 (2001 +)
LS6 valves are 0.6mm or 0.023622" longer, hollow stem intake, and hollow stem sodium filled exhaust valves.

Stock LS1 Heads
Chamber 66.67 cc
Intake 200 cc
Exhaust 70 cc
Valve Diameter Intake 2.00"
Valve Diameter Exhaust 1.55"
Part Number 12559853 (1997-98)
12559853 (1999-00)
12564241 (2001-03

Oh and ls2 heads are 243's as well...

mikesfastss

lmao,sorry fellas they were 241 castings,its a 2000 motor from corvette or f body from what i found on the internet. thanks for the help though