@bosswrench posted:I think Larry Stock at Pantera Parts Connection (www.panteraparts.com) in NV still has an unused NOS pair of aluminum Ford/SVO A-3 heads at his shop. These were pro racing Cleveland heads in the '80s and were quite popular until Ford stopped supplying nearly all Cleveland parts decades ago. The A-3s were the largest port volume (but still smaller than any iron heads), with 2.19" intakes & 1.73" exhausts. They feature relocated ports, Boss 351 architecture and use a specific open plenum 4bbl intake or Weber/EFI. Good luck.
I am running A3 heads and if you can get a set, highly recommend them. There are only two intakes for them though.
The M331 single 4 "Torker" and Halls High port Weber manifold.
I tried both and stayed with the Webers.
If you go that route, be advised that the exhaust ports are raised about 1" and the bolt pattern for the exhausts is a little different then the iron heads.
You would be bolting on an easy 30hp gain over the best iron heads. The intakes flow 330 out of the box so you need a 600 lift cam with them and 2" primary tubes on the headers. I went with 180's on those.
The combination of the heads, induction and cam change is likely closer to a 150hp gain.
If you can get the A3's, go for it.