Planning 318 build for daily driver

250-275rwhp with just a 360 4bbl cam? or what are you basing that number off of? anyone have the specs on a stock 360 cam on hand?

What is considered good mileage for what you are looking to have?

Werent 302 heads around 1.70's as far as intake valves? A popular mod to them is 1.88's for intake, those little stock valves wont flow much in the upper rpm.

My 318, DAILY DRIVER has a .480lift 280duration comp cam, performer rpm, headers, and 2.02 j-heads dynoed at 240rwhp at 5,300ft elevation. corrected was about 280rwhp. This was with some really oil caked intake valves however that were limiting things i'm sure. also the timing was very relaxed for what it is now. Anyway, it should dip into 13s the next outing with 5,000ft air in a 3,600lb car. and it is driven/abused daily. (Quote)


Goody's,
The stock cam is/was .410/.410 252/252 @ adv. 108/111 CL for the 360 the 318 is .373/.400 240/248 @ adv. 110 I/ 108 E CL I don't know why they did it this way, it may be a misprint. This cam would be a considerable step up for the 318 as the duration @ .050 is this the 360 has 203/203 and the 318 has 181/192 which is a good bit more and for the little engine is a bunch for the street. The 318's are the easiest to over cam and most people get carried away with them.
The 302 heads did have 1.78 Intake valves and 1.50 exhaust valves stock, and as you say the first step that people do is to install the larger valves, but what people don't realise is the fact that the velocity slows way down when the larger valve is used in a small port head. Let alone the shrouding factor that happens both in the chamber and in the cylinder. But this pertains only to the intake side as the valve is larger, the head can benefit from have a larger exhaust valve as the port is somewhat restricted and this helps a bunch.
This is what we found over the couse of a few years and the mod's done. First the 318 heads with 1.88/1.60 valves on a 318 .040 .480 hyd. cam and adjustable valve train but not rollers. The 318 ran 8.28 best with the 302 heads and larger valves. Then we went ot the 360 heads with Bowl Blending and gasket matching which was done to the 318/302 heads also, the 318 heads have 132 ccs intake port runner and the 360 heads have 156 cc port runners the 360 heads ran 7.93 best. But then we went back to the small valve on the intake side in another set of 302 heads with the same amount of work done and tried them and low and behold the small valve heads out ran the 360 heads by what I would call a bunch the best was 7.66 and the port runner was 136 ccs it picked up the cc's due to the shape of the valve, a lesser tulip. These are 1/8 mile times and in a 70 Duster @ 3100 lbs. The 318 that was used came from my daily work truck with a 100K miles on it it also made 15 mpg on average. What we found is that the small valves made 25 more ft. lbs. of torque and 30 more HP so this is where I base my claims. This was also between 4000 and 4400 ft. elevation corrected with high heat and humidity here in Atlanta,Ga. in the summer time.