Hi I was wondering if any one knows what these heads are from the casting # is 1241860and the valves have GM ontop and an I or 1 ond the face of them and from what Ive seen in other posts may be the same size as stage 1 valves, is this possible ? The guy I got the motor from said it was a stage 1 but he also told me His skylark was a GS...... any info will be helpfull , thanks P.S. one head has a#1 over the casting# and one of them has a #2
Stage1 valves are setup so that when they are installed, you can barely fit a dime in between the intake and exhaust valve. Non-stage heads have nearly a quarter inch between the valves. The casting number indicates that your heads are for a 73-74 block.
The 860 head is a 73 or 74, the only way to know if it's a stg-1 is to measure the valves, stg-1 will be 2.125 on the intake and 1.75 on the exhaust. Jim Burek P.A.E. ENTERRPRISES
the valves measured as listed.... also about the stampings that read GM does this matter ? and could these have come this way or installed by someone? thanks the dime didnt fit either
Good!:TU: Check this page out - it has pictures of ctandard, stage 1 and stage 2 heads and valves. http://www.buickperformance.com/455hdcompare.htm
I guess my next question is were these valve sizes offered in 73-74? or is there any possibility of these being low production?The block says xa and a member or the board says that is the Riv. prod. code . I have the crank, pistons and rods, main caps, original rocker assy. ..... The heads have been apart because there is no carbon deposits on valves. are there any other parts that would have been specific to this engine , I know 73-74 wasnt considered good by smog/comp. to the 70 but most of that can be fixed ...It would just be cool to have finally scored something in my favor... P.S. sorry if Im asking alot of questions, I have a 69 GS 350 that is matching # down to the carb, and we are in the middle of a frame off , I didnt want to change to a 455 untill I tripped over this one . The car wont be 100pt. show machine , I plan to drive the wheels off it (literaly) and even race at the nearby track...Im shooting for KY!!!!
XA code is the Riv GS engine....was offereed as a performance motor option from the standard 455. All of these Riv GS engines were SUPPOSED to have Stage1 valves installed, but some of them leaked out of the factory without them. So, yes I would say its a fairly rare find you have.
thats great !! Its not often you buy something without actualy knowing what your getting and it turns out better than you expected... This guy thought he'd pulled one over on me >>> for 500.00 I got a 70 GS hood with scoops, the 455 components, a brand new performer intake, and a 72 skylark shell........
