So as I've searched the internet it would seem that the 317 heads are best suited for boosted applications when bolted to a 5.3L engine because of their large combustion chamber size. I've also read that some head milling and flat top pistons can help mitigate this. I've also read that the larger valves over the smaller bore of the 5.3 vs. the 6.0 from whence the 317 head came can cause shrouding.
My budget would really like me to make due with what I have, which is this. 5.3L block, 317 heads, truck intake & drive by wire throttle body, power glide transmission (newly rebuilt with stock gear ratios), as of yet undetermined final drive ratio (rear end gear ration, wheel and tire size not yet finalized).
Here is the application. 1940 Chevrolet 1/2 ton pick up. Patina truck not a rat-rod. Should weigh just under 3000# when finished. The goal is for it to sound nasty, be very hard on tires, and a hell of a lot of fun to drive. Not intended for long trips. A few hundred miles in a shot max to an event or whatever.
Machine work is being executed by a reputable local engine machine shop. The heads will be surfaced for flatness which should help boost the CR and we'll go with flat top pistons for the same reason.
Bottom line is this - the universal opinion seems to be not to use the 317 heads on a 5.3 unless you are boosting. Is this gospel truth for those of us who won't be racing and geeking out on every little detail every weekend and constantly upgrading and tweaking things for a few extra HP and to shave a little off of our ET? Is this really going to be a dog? Is the valve shrouding the kiss of death? Assuming this combo isn't the biggest mistake ever, what cam get's me where I want to be? I was kind of leaning toward Comp Cams 54-416-11 until I started to get nervous about the heads. http://www.compcams.com/(S(10nkh0ib3...csid=1087&sb=0