Wow, got a rebuild kit from Cliff's, truck runs awesomely now that I have the right jets in there, and adding access to APT was a good upgrade. Carb is 17059205, from a 79 chev truck, originally 0.052 rods and 0.072 jet. Initially went to a 0.074 jet but was too rich, so the 73's are perfect now.
Engine is 350 chev, 4-brow flat tops with Vortec heads meticulously prepp'd by me 3 angle cut and blended in the bowl and top-angle to chamber is slicker than a brook trout. sharp chamber edges removed, esp. excess spark plug threads , smoothed. Cam is XE-250-H from comp, truck is 67 K-20 chev longbed, weighs 4950 lbs, axle ratios are 4:55. Dual plane edelbrock v-tec manifold. Comp measures just over 10:1 on my gauge when I crank the motor with ign. disconnected. Initial timing 9 degrees w/ vac disconnected. Never pings, even running 87 in hot Texas summer. Chamber smoothness, but also figure ethanol gas can now have a lot more water in it (oil companies sellin me water at $3.50 a gallon, probably added to some extent), so remember the old "water injection" systems to reduce ping ? Guess what ? Its inherent in the fuel now.
anyhow, I'm wondering about secondary rods. Spec for the carb I have is DP, which are in there now. I'm pondering putting in these DR rods I have sitting here. sure, easy 3 minute job but before I do it, I thought I'd throw out there a question of .... is that a decent idea to move from DP to DR ? Truck is used mostly for towing, although I do enjoy the tremendous amount of "scoot" it now has. lol, squeals the tires with little effort, could probably lay rubber but I too old, plus i like my tires
edit + : Here's the dyno sheet for that cam, Tq over 400 ft.lbs. low rpm is where I like to live, don't care about how many ponies it makes at 6500, I never go there.
http://www.compcams.com/Technical/DynoSheets/XE250H-10_001.asp
