will all the different alum. LT1 heads fit any LT1 short block??

[DRAGIN]

i am going to a swap meet this weekend and hope to find a set of aluminum LT1's to take to have ported so i have no down time on my TA. i just wanna be sure since there were several different casting #'s for these that the earlier and later castings will interchange. (are essentially the same bolt on wise) on my 94 shortblock once they are ported and set up.thanks for the help!

[Injuneer]

All LT1 aluminum and iron heads, and the LT4 aluminum heads will bolt directly to any LT1 block, with no problems. You can not bolt an LT4 intake to LT1 heads though, without some minor machine work.

Just make sure you aren't looking at LT-1 (note hyphen) iron heads, because they are Gen 1 SBC heads, used on the 1970-73 engine called the LT-1. Also make sure you are not looking at the iron heads from the 265CI L99 engine (aka "Baby LT1") used in the B-Bodys.

The bolt pattern is the same on all Gen 1 and Gen 2 SBC heads. Its the LSx series of engines (Gen 3 and Gen 4) that have a totally different bolt pattern and port arrangement. The cooling ports are different between the Gen 1 heads and the Gen 2 heads, and that's what make them not interchangeable, without revising the coolant passages.

[Wild Willy]

The iron heads used in the B-body flowed better, and, I have to believe, were more durable- they were used for police service, after all- the B-body LT1's really had great torque to move that over 4000 lb pig pretty good-

[Performin Norman]

Heck, they even fit old school small blocks. My buddy was running them on his 350 chevy for a while.

[FroSSty]

Heck, they even fit old school small blocks. My buddy was running them on his 350 chevy for a while.

More info please... Machine work needed? What intake? etc.

[Craig 94 TA GT]

Not to get off topic, but as Fred mentioned, the cooling passages must be revised for SBC style heads to fit. I recall someone on cz28 got a set of race used Cup heads from Petty Motorsports. I'm guessing this had to be from a Chevy motor, but I know they run Dodge. Petty is not the greatest in hp, but the heads still flowed around 380 CFM (I believe other teams are well over 400). After he put that and a ported out restrictor plate intake (for clearance in the 4th gen), he made tons of power N/A.

[Performin Norman]

More info please... Machine work needed? What intake? etc.

I don't think he had to do a thing but bolt them one. He was running a carbureted Edelbrock intake (old school)

[Trash man]

I don't think he had to do a thing but bolt them one. He was running a carbureted Edelbrock intake (old school)

i beleive all you have to do is plug a water jacket on each head, im not positive but i remember reading somewhere bout that, i was gonna do that to my 406 sbc in my garage

[DRAGIN]

thanks for the information.

it is good to know the iron lt1 heads would also fit but i am out to find a set of 93-97 aluminum lt1's so that delets the l99 cast the 70's LT-1 and the other cast lt1's.since i will be able too put hands on them as well as having the proper casting #s i should be safe. and if i cannot find a set for a decent price at the meet i'll keep looking. thanks for all the help and advice folks!

[Craig 94 TA GT]

Also to note, if you will use LT1 heads, make sure to ONLY use casting #s 10207643 or 10128374. I believe they are from '93 to '94 (could be 1995 too, but I'm not sure). The other castings have too little material and cannot be ported out as much.

[Injuneer]

If you hold the LT1 head gasket up to a Gen 1 SBC head gasket, you will see the differences in the coolant porting. You plug up a couple holes, and drill a couple holes and they will bolt on. Its a very popular upgrade for economy Gen 1 builds, because the LT1 heads flow like the iron Gen 1 Vortec heads, but are aluminum, allowing a higher compression ratio.

That holds for the LT1 iron heads as well. They actually flow about 15CFM more than the aluminum heads. But they do not offer the same heat transfer advantages that allowed the aluminum head engines to run 10.5:1 compression ratio. The B-Body engines had lower compression ratio, and lower HP. The added torque was due to the cam specs, selected to allow the engine to move the 4,200+ # mass of the B-Bodys off the line.