Edelbrock heads question

Are those 3/8 pushrods? I picked up a pair of the same heads and first thing I noticed is that small pushrod tunnel. Doesn't look like much room to ream em either. I run a 3/8 pushrod. Pretty high spring pressures....hope this doesn't become an issue.

Currently running CNC'd Indy/RHS heads. One good thing is the pushrod tunnel is plenty big.