5.3 Turbo Heads
Thread Starter
Teching In
Joined: Jan 2022
Posts: 12
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5.3 Turbo Heads Hello All,
working on rebuilding my 5.3 for a turbo build going in my 1979 Malibu. Was wondering if it is worthwhile to change out my heads as the engine came with the Castech 706 heads. Definitely looking to run a good amount of boost through this engine (15-20lbs) so I'm thinking they'll be no good and crack on me. What would be a suitable upgrade or should I just leave them and hope for the best? Car is going to be street driven most of the time.
working on rebuilding my 5.3 for a turbo build going in my 1979 Malibu. Was wondering if it is worthwhile to change out my heads as the engine came with the Castech 706 heads. Definitely looking to run a good amount of boost through this engine (15-20lbs) so I'm thinking they'll be no good and crack on me. What would be a suitable upgrade or should I just leave them and hope for the best? Car is going to be street driven most of the time.
It was the very early castech heads that were the issue. If you have that early of a engine, you have head gaskets that will HAVE to be changed for boost, and then you'll also have a rod limited setup as well, so.... Do you know exactly what year it is, or just kinda guessing?
Thread Starter
Teching In
Joined: Jan 2022
Posts: 12
Likes: 1
I know that its a LM7 out of a 2005 sierra 1500. It has the later gen 4 rods but all the old 24x sensor etc. I looked at the service bulletin for the heads and it says up to 2006 was affected but I wasn't sure if that was true or just a vague guess at when the problems stopped happening. It definitely has the castech logo in the heads so thats why I ask. Just don't want to button up the car and then 500 miles later or something they start leaking like crazy
