The "Throw Away 318"

Dave_J said
I fixed that in BOLD for ya. ;)

We put some 1.88's and 1.60" in a set of closed chamber 273 heads and did just a little unshrouding. Using a SP2P 318 intake and a 500 AVS made a mild RV cam'ed 318 real responsive down low for a small Airstream's Fury wagon tow rig.
Later 273 open chambers were not any better than 318 open that we could see. The 1.78" and 1.50" valves were not up to power.
Click to expand...

68 and 69 273 heads are just 318 heads, same casting number. I don't consider them 273 heads ;-) Now, if you take a 68 or 69 273 and put closed chambered heads on them, you will have something since the pistons are about .030 higher in the block.