gunter96ws6

iTrader: (12)

there is a local guy selling a set of lt4 heads. id love to buy them because the asking price is very fair. how can i tell the difference between an lt1 head and an lt4 head. i dont wanna get fuct and end up with a set of plain ol lt1 heads. thanks fellas

JAKEJR

Start with checking and verifying the casting number.

Jake

gunter96ws6

iTrader: (12)

that was my first thought jake, i was curious if any of you knew what numbers to look for. i can only assume that it dosnt say lt4 on the head itself, nothing is that simple.

RamAir95TA

iTrader: (2)

The LT4 heads came with 7/16" rocker studs. They should also have p/n 12555332 cast into them.

gunter96ws6

iTrader: (12)

thanks joe, thats exactly what i wanted to know

GIZMO

iTrader: (8)

No they didn't. The GM Performance heads have 3/8" studs.

RamAir95TA

iTrader: (2)

I was quoting the popular LT1 vs LT4 webpage. Check this link, about halfway down:

http://www.grandsportregistry.com/lt1vslt4.htm

Both the LT1 and the LT4 Heads accomodate 7/16" studs but the LT4 has larger 7/16 rocker studs. There are some reports of early LT4's with 10mm top threads. The LT1 studs are 3/8" on top and 7/16" bottom. GM part numbers are #3921912 for 7/16" LT4 and #1255216 for 3/8" LT1.

GIZMO

iTrader: (8)

I am looking at actual, real live, LT4 heads. The casting number is 12555690. And, yes, they came from GM with 3/8" LT1 studs.

gunter96ws6

iTrader: (12)

i dont think they are lt4 heads. the cast #s he gave me are 10128374. any idea what he has?

RamAir95TA

iTrader: (2)

374s are typical LT1 heads.

gunter96ws6

iTrader: (12)

Camaro350z2897

iTrader: (2)

ya, and the lt4 heads actually do say lt4 on them

GIZMO

iTrader: (8)

It seems that some do and some don't. On the one that I have that you can see the marking, it is very hard to read (It says LT-4, not LT4).

gixxer75094lt1

iTrader: (8)

just be glad u didnt end up buying them and got screwed.

gunter96ws6

iTrader: (12)

oddly enough i found another set that included the intake manifold and throttle body. these are even ported with some badass beehive valvesprings in them. i bit more expensive than the others but well worth it.

89BANDIT

Unless you can get them really cheap, And not have to put alot of $$$ into them. Dont bother with GM heads. The aftermarket stuff out there will outflow any LT1-4 heads. Go check out AFR and TrickFlow. Match the cam, and bolt and go.

RamAir95TA

iTrader: (2)

I strongly disagree. It isn't always about flow and flow only. Ported stock castings, for the money, offer the best bang for your buck with immensely impressive results.

Puck

iTrader: (17)

+1

Unless you are going all out, ported LT1s are fine. Ported LT4s even better.

Camaro350z2897

iTrader: (2)

ya sorry, the ones i just sold said LT-4 on them. Pretty clear on mine but of course that will vary. All the pistons out of my motor read LT-4 as well

GIZMO

iTrader: (8)

This kind of information is good.

Do the LT4 pistons that you have include smaller than normal valve notches?