FYI: Cleveland 4V heads feature larger ports/valves than the Cleveland 2V
heads. The 70-71 Cleveland 4V heads also feature a closed or quench-type
combustion chamber - 2V heads feature an open combustion chamber. 2V heads
also feature non-adjustable rocker arms.

Cleveland 4V intake diameter 2.19", exhaust diameter 1.71"
Cleveland 2V intake diameter 2.04", exhaust diameter 1.65"

Yet another $.02 worth from a proud owner of a 1970 Mach 1 351C featuring 4V
heads @ http://community.webshots.com/album/18644819fHAehGJAjt

"Dean" > wrote in message
...
> Found a Q code 73 Mach-1 in a salvage yard. Not much left of the car, but
> got the engine and trans for $325. When I got the engine home checked the
> casting number on the block D2AE-CA this checked out, Intake manifold was
> 4bbl spreadbore. All seemed good until I checked the Heads. They had a 2
> in the corners, which means 2bbl heads. So you mean to tell me that
> someone removed the 4bbl heads and placed 2bbl heads back on, and left the
> 4 bolt main block and 4bbl intake. I guess this is possible. Was planning
> on placing this in my 71 coupe and taking out the original 302. I guess
> my guestion is, is this how you tell the difference between 2bbl and 4bbl
> heads on a cleveland?
>
> Thanks Dean.