Question re: heads for my 300 hp '63

[63split]

Can anyone out there verify that 461x (3782461) heads were correct for my 327/300hp '63 SWC, powerglide tranny, build date of Mar 11, '63?

Before banging my head against a wall looking for a correct dated pair :Wthought I'd check to make sure that's what I need. What makes me question it is that the manifolds were different for the 300 hp, depending on if you had the 4-speed or powerglide. But everything I've read says the 461x's went on all 300 hp's, regardless of tranny. Motor has 3795896's on there right now. Thanks guys...

 

[JohnZ]

Yes, 461's were used on all 63's except the 250hp, which used the 896's. For the exhaust manifolds, all 250hp engines and 300hp Powerglides used 2" outlets, and everything else used 2-1/2" outlets.

 

[63split]

Thanks John. As I start my 461x search, what should I be looking for as far as 62cc vs. 64cc, 1.94 & 1.50 intakes vs. 2.02 & 1.60's etc.?

 

[JohnZ]

Thanks John. As I start my 461x search, what should I be looking for as far as 62cc vs. 64cc, 1.94 & 1.50 intakes vs. 2.02 & 1.60's etc.?

The 300hp 461's used 1.94"/1.50" valves, and the others had 2.02"/1.60" valves. Factory 2.02 heads had an extra machining cut adjacent to the intake valve to unshroud it (photo below); heads converted later from 1.94 to 2.02 by machine shops generally don't have the unshrouding cut, and flow less air than the original 1.94" heads did.

 

[63split]

Thanks John - this is exactly what I needed to know. Now - if I could just find a matching set of dated 461x's...!

 

[JohnZ]

Thanks John - this is exactly what I needed to know. Now - if I could just find a matching set of dated 461x's...!

The casting dates on the heads don't need to match - they hardly ever did in production, except by coincidence; they just need to be cast prior to the engine assembly date on the pad.