A460 Heads

Trick Flow says that an a-head with 2.35 intake and a 1.88 exhaust can be used on a min bore of 4.39. What would be a good smaller bore to use and still be able to unshroud the valves? Seems that a 4.39 bore would choke some of the air flow.

Smaller than 4.390?

No, say like a 4.40 bore, how would that affect a set of full ported a460's?

i run a 4.440 bore but also 2.3/1.88 valves.more bore would be best i'd think.

4.400 is bigger than a 4.390" bore.......better but aint gonna move the needle for air flow.
4.500" is good for the A460 stuff and i.m.o. 4.560" is getting to the sweet spot .

Lem Evans wrote:4.400 is bigger than a 4.390" bore.......better but aint gonna move the needle for air flow.
4.500" is good for the A460 stuff and i.m.o. 4.560" is getting to the sweet spot .

thats why i did'nt put 2.350's in when i had it down last year.lol.

Ok so a 2.3 valve would be better sutied for 4.44 bore or smaller? I am looking into my new build and with the p51 heads on a "don't know when more are going to show up list" I want to do the A460 head. I am starting with the top end this time and going to be using a 4.3 crank. I want a A460 block but I am also looking that if I can't flip the bill I will use my block I have now so bore size is up in the air right now. I just don't want to hog a factory block to the max and leave thin cylinder walls. I am not doing a max effort, just a conservitive build, 12.1 compression give or take some, but I want to have the top end to F L O W. Lem has been so helpful on my SCJ build but this A460 stuff seems to be major leauge.

just some food for thought,the block would be my first plan.i started my 526 like you,with good A460 heads.i used a 4.250 crank,long story,and a dove block with 2 bolt main.it's been fine for a lot of passes but i always wished i'd went with a better block or at least 4bolt caps.another way to look at it is with less cid you may need to turn it higher to make the power you'd like.to get what the A460's have to offer you need to use the airflow,cid or rpm.just my thoughts.

In my opinion, 11.8/1 to 12.5/1 compression ratio is one of the most useless ratios to have ... it's to high for pump gas and when using race gas it should be higher.

2.300"/1.880" is the way to go; (or buy 'em bare and use 1.840" exhaust valves for the smaller bores).

Thanks for the input guys.