BE AWARE!!!
I've built dozens of common Chev and Ford V8s, much less of MoPars, and a few oddballs like '50s Caddy 331s, straight 6s, V6s and various 4 cyls. The biggest headache I ever had was a 351 Cleveland!
It was the flat-out Big Boy with monster valves and absolutely HUGE ports. The customer wanted to stuff it into a '68 Mercury Cougar.
One machinist in the shop ground and balanced the crank and another bored and honed the the block after I had decked it. I milled the heads, smoothed out the ports and combustion chambers, installed new valve seats and guides, then assembled the heads with the hardware the customer provided.
I put the engine together with no problem. THEN... I was presented with the intake manifold that the guy wanted to mount. Okay. Problem was that the angles of the manifold runner faces were WAY off from matching the faces of the intakes of the heads!
I presented the problem to the boss and showed him what was going on. He called the customer and they went back and forth over the phone. The customer insisted that THAT was the intake he wanted to use, and nothing else! So, where did that leave me?
It took me a bit to dope it out. What I did was mount the intake on the head mill and squared everything up, then did a whole lotta measuring and figuring on mating angles with the cylinder heads. Very carefully, I milled only a couple of degrees at a time from each runner face at the appropriate angles. I was lucky that it only took two runs through the mill for everything to fit perfectly.
THEN came installing the engine in the Cougar and mounting the headers... another real PITA, But that's a totally different can of worms.
All this leads up to my advisory: Make absolutely certain that you purchase the intake that matches the angles after the block is decked and the heads are milled and cut for flow.
Just sayin'.
