i talked to TA, Michael says he's busy working up all of the relevant specs on the new castings ( CNC has been changed and they need to re-verify all of the as-built specs ). he's also going to work up a spec list on a raw factory casting for comparison's sake.
he said that the provisional numbers were about 209 on the intake and 114 on the exhaust with a 54.8 cc combustion chamber. oversize valves are a $100 upcharge per head, which is pretty much a given that you should do since they moved the valves onto the centerline of the piston so you could get bigger valves in there.
the aluminum castings are taller than the cast irons, which necessitates longer valve stems and head bolts. the factory dimension parts aren't going to work with them.
he was quoting prices off the top of his head, so don't hold them to these specific numbers:
$2800 for a pair of bare heads
$3800 for loaded heads
$4000 for loaded big valve heads
well, it's always nice to get a surprise like this. i don't know if i misheard or if he was suffering brain fade after a long week: "Bare castings are $1650, assemblies are $2800"
or, shucks, it's that old sales gimmick of setting the price expectation high and then offering a discount.
"TA Performance “Budget Bowl Blend” is a new introductory low cost porting option that we’re offering for customers who choose to have us assemble their 350 heads. For $200 we will port your heads which will result in average gains of 10 cfm on the intake and 25 cfm on the exhaust. Our next porting option is a Level 1 for $700.
The TA 350 Stage 1 SE heads are machined to accept stud mount (Chevy style) rockers. All that is required is that the rocker towers are milled off. You can take the heads to a machinist and have them do it, or TA can perform the service."
Below are stock iron heads compared to ported iron heads by various Buick engine builders
so basically, TA is saying that their Aluminum heads will flow better out of the box than all but the most extreme porting job on a cast iron head.
when they get time, they expect to be able to get somewhere in the vicinity of 280cfm out of an intake with a Level 3 porting job.