Craig said these are actually a damned nice set of heads for being "vintage". These were made before people started using the 5.3L heads and the chambers were welded up to reduce compression and he milled them to get to 11.4:1 CR. Not sure what the compression would be on a 5.3L but I would guess at 10.8 or so?

The original owner made 436rwhp/419rwtq on a 6spd car.

Ohh, I don't have the full sheet scanned yet but the main #s were:

Peak CFM Intake: 307@.600lift or 296@.550lift
Peak CFM Exhaust: 220
CFM Avg. 252

Heads were sent back to GTP for inspection and a thourogh cleaning. New Comp Double springs (good for .650lift) were installed. Never been reinstalled since.

$1700 +shipping. When new they ran $3200, I paid $2800 for them used.

 

Do you know the chamber size on these?

 

what bore are these meant to fit alos?

 

I'm not sure of the chamber size. They were standrad 5.7L LS1 heads but had been welded up to simulate a 5.3L head. they are setup with 2.02 valves and were made to run on my T/A. I will call Craig and ask him any tech questions you might have so lets get em all lined up so I only have to call once. LOL

Hmmm, now I'm starting to wonder if they are 2.05 valves. God I have a horrible memory.

I'll call Criag again and get the full specs on them. All I know for sure is they made great power!