2.02 valves and 5.3
That along with 1/2” studs and the new BTR small bore LS9 type gaskets ought to be pretty bullet proof for sealing.
Not that I’ve had issues as it sits.
Question is, do the intake valves clear the bore?
More than a few aftermarket heads have even bigger than 2.02.
I understand that if they clear, probably affects airflow a bit, but it is a turbo motor.
Ron
That along with 1/2” studs and the new BTR small bore LS9 type gaskets ought to be pretty bullet proof for sealing.
Not that I’ve had issues as it sits.
Question is, do the intake valves clear the bore?
More than a few aftermarket heads have even bigger than 2.02.
I understand that if they clear, probably affects airflow a bit, but it is a turbo motor.
Ron
I recognize you from YB.
As I was poking around, most are on back order. Just goes with the times I guess. This will be a winter project.
Thanks again
Ron
Have you messed with or considered the 240 small bore rec port heads? Curious if they would fit with a reduced intake valve also which might open up some other intake manifold options also.
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That said, I've been looking into small bore cathedral ports heads for my next engine (LC9 forged), and seems like the consensus is that TFS 220s are a very good bang for the buck, thicker deck and all, but not much of a power gain. Mast, Brodix heads show a power gain but are near $4K. Mark Enwia is promoting some new heads too, might be Australian castings of some sort I don't know the deck thickness but the price point is interesting.
If I bought the as cast 220’s, I’d prefer them bare, with powdered metal guides.
Any flow improvement over my ported 799’s would be a bonus.
Its a moot point now, as they simply aren’t available until sometime next year
Last edited by RonSSNova; Oct 7, 2021 at 04:17 PM.
But Jon Capizzi (do you know of him) picked up power a set of Mast heads, pretty substantial.
But Jon Capizzi (do you know of him) picked up power a set of Mast heads, pretty substantial.

Sounds like Ron has a forged alum block 5.3 with stock head castings. He can somewhat cheaply get some TFS 220s, and push him combo with a bit more confidence.
For him to go 6 bolt, he'd at a minimum get an LSX block which after a bit of machining, assemtly and he'd need to get a set of 6 bolt heads too. LSX block is like $3K right now, a Dart block is more and much more for aluminum.
Going 6 bolt is usually a big jump for most folks. A buddy of mine told me the B15 crate motors used to be a hella deal in the past, like $8K.
So after this last weekend, I think I have enough power to get near 8.50, if I don’t tip the car over in the process.
Since I have to yank the engine to fix the pan studs, I’ll just get the new small bore BTR 9 layer gaskets and call it good.
If I stumble onto something aftermarket that is used for a good price I’ll consider that.
It’s a little hard to believe that the TFS220 doesn’t outperform 799’s, unless that was assuming CNC ported 799’s. I ported mine, they have a fancy valve job, but no clue what they flow.
So for guys wanting to push the stock block stuff (forged rotator) a little farther the thicker deck TFS heads are a good compromise to promote more head gasket strength while not spending the considerable coin on a complete six bolt setup.
Is that a correct interpretation?
I'm asking because I already have the rod/piston 5.7 with CNC ported 243's so if I was to make a change I'd also consider the TFS head because a six bolt setup is not in my future anytime soon.












