Check out our FED-L83 CNC Head programs. With a huge in stock inventory for those wanting to do core exchange or wait 7-12 business days to get your done. Flow numbers will be posted shortly.

 

Tbis is something I'll need soon. As I'm in California and cant have headers. Any little bit will help. And pass smog still

 

Very interested in pricing and flow numbers.

Do you guys know if the L86 heads go right on an L83? I wondered if the valves were too big and if there were any other differences. Those flow a lot more than L83 heads from what I've seen so far and was wondering what will be the popular way for us L83 guys to go, whether it be ported L83's, or ported L86's for double (double as in more flow in stock form then even more from those being ported) the gain in flow or..

 

l86 heads do not but l86 cam will

 

Thanks. What stops the L86 head from going on/what is different from the L83.

 

Valves wont clear the bore.

 

Any other differences you know of? I wonder if an L86 head with a smaller valve would be a bang for buck combo is why I ask.

 

I don't know but that be awesome especially with a pd blower where low end is in abundance. Now I want to know too.

 

I've really wanted to know because if I remember right the L83 head flows around 28x cfm and the L86 flows 33x, both in stock form. And stock GM castings aren't all that expensive. I saw that one outfit got the L86 to 345 cfm and someone else got 36x cfm. But 33x is f'ing moving air in my opinion so stock castings would be a great improvement over 28x L83's.

Bowl blending and valve job is a large part of the power increase with ported heads and not too big of an expense. So I've been thinking maybe L86 heads with a smaller valve bowl blend and valve job could be one bad *** setup for low $$$.

I've also been thinking a LT4 take off blower would be flipping sweet on one of these trucks.

 

I'm sure the larger valve plays a major role in those flow numbers. If I had to guess going to a smaller valve in the L86 head would net you flow that is similar to a ported L83 head. it could also be an issue of valve placement that would make them less than ideal on the 5.3 bore.