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anyone know anything on a # 3973487X head, all i can find is that it was a 68-73 350 lt-1 head, but the X is supoose to mean 10cc port port volume, suppose to be 330-350 hp head, was cast on Oct 19th of 1971,i also have the 1.94/1.5 valves, one site claimed that the 487x casting had 2.02/1.6 but thats false. but was a lt-1 vette head.
That casting was actually used in about 71 and 72, the last of the years of the LT1, after it got smogged like everything else. I don't know about it being around before then. They were decent heads as far as flow; not the best, but pretty good.
On the other hand, their chambers are so large, it's impossible to get decent compression with them, unless you're running a 400 or larger motor, with flat tops; or you use domed pistons which is a highly inferior way of raising the CR.
They sell easily to people with the old LT1s though, for good bucks; that's what I'd do if I had one (!), go advertise on one of the sites that caters to older Camaros and Vettes, or in Hemmings, or the like.
__________________ "So many Mustangs, so little time..."
If the heads have the extra steam holes in the deck they are off a 400ci motor. Chamber size could be as big as 80cc. Not bad on a flat top 383 or 406 motor with porting and larger valves etc. If you're building a 350 then starting with a 305 HO head (small chamber) is better.
Great for a blown or turbo 350 project thou.
"487" – 3973487, OR 3973487X. The regular casting was found on the 1971-1972 350 LT-1 engines, had 1.94/1.50" valves, 76CC combustion chambers, DO have accessory holes, intake port volume should be 161CC's, exhaust port volume should be 65CC's. The 487X had 2.02/1.60" valves.
btw just finished up the d/s head, all nice n shined up and fresh valves, springs, n seals, just the other argh
Last edited by trans_am_racing; 10-17-2004 at 12:16 AM.
