cantbuytime79

THis swap is for a 1994 Mustang GT. Will be driven often, going with FI and no boost. Plans are N/A, big cam, ported 706's and LS1 intake with Mid length headers with a glide trans.

What is the difference in the 5.3 L33 short block and the 5.3 LH6 short block? Looking to buy one soon. Just wondering if one had an advantage over the other.

I have an iron 5.3 short block with 70k on it. Its very nice but I really want that weight savings.

cantbuytime79

No one knows the difference in the two aluminum 5.3's?

All I know is that one is a Gen 3 and other a Gen 4.

claytonisbob

iTrader: (1)

I believe the L33 is more of a HO engine with a little higher compression (ie flat-top pistons) and better heads (799's). The LH6 is just an all aluminum typical truck 5.3. I'd assume being a gen iv, it has a 58x reluctor wheel, so you'd have to have an ecm to accommodate that. My choice would be the L33.

If you're throwing some ported heads on it I don't think it would matter all that much. If you can get your hands on a L33 or LH6 that would be great, but honestly if you already have an iron block 5.3 I'd just run with that. It's a lot of investment to only shave 60lbs. Install some 4.8 pistons and you'll get your compression bump.

cantbuytime79

I have been reading and scouring through numerous threads and post. All I have learned is they are both flat top piston engines, The knock sensors and timing sensors are in different spots on both engines. I thought I read that one engine has better rods?

And the LH6 was rated with 5hp more.
Found this:


I got a friend who wants my 5.3 iron short block. Says he will give me $325 for it. Another guy we know has a 55k mile short block LH6 out of an 08' Avalanche. He wants $375. has all the covers on it.. I am guessing the newer harness and computer is whats going to cost me more if I go the LH6 ??

I know where an L33 is for $400, its got no covers, oil pan, or windage tray. It would def cost me more to go that route. At first I was looking for just the L33 block to swap all my stuff over from the iron block, but being that everyone is asking $300 plus for just a L33 block. I just didnt see it worth it to go that route..

Thanks.

TomM

iTrader: (56)

See the attachment...

T,

Bo185

The LH6 should be Gen IV with 24x as it as an early Gen IV, but it will have AFM (DOD) as well. But if you changing the heads not be big deal.

Block difference is L33 is Gen III and LH6 is Gen IV.

The L33 is really higher compression ratio more than the LM7 MG had to add the 4.8L flat tops to maintain CR when switching to the 799/243 heads as they have larger chambers and it would have drop CR.

I would go an L33 as its a Gen III.

cantbuytime79

Ok, so let me ask this. If I go with the LH6 (58x wheel)I would have to get the Lingenfelter 58x to 24x computer adapter to be able to to use drive by cable? Or can I just swap the 58x wheel for the 24x?? Of course I would remove the DOD stuff as well.

I do see why L33 is suggested. Lesss stuff to deal with.

Jj Tauer

Ls7colorado

iTrader: (3)

I dont understand why someone would respond to a 9 year old thread with false information...... L33's have gen 4 rods