The always elusive CAM question..

[340RULES]

Pops6T6,

I agree with Rusty and Mopar on this, and most everyone has their own advise building their preferences but I believe it's necessary benefit to know your CR. I would zero beck the block per Rusty, great info!!! What he wrote is exactly what was done to my 340, CR is about 10.25 to 1 with KB 107 fitted with a 49000 head gasket with a Eleb performer and equipped originally with a 680 holly vacum secondary. IMO previous owner over cammed without actually doing some homework , therefore he popped in a purple 292/508 with what a 2000 TQ - What a slug!!. IMO the carb selection wasn't proper for the build, Car was fitted with an 8.75-3.23 (thats a good gear for BB's) sure grip and 727 Streetfighter. Car was a absolute pig off the line and would eventually pull kinda OK at 3500.

Like you I'm not going to beat my thousands invested on the drag stripe, but I want performance for the street with an awesome sound: I keeped the cam (Sounds great) plus i like old school **** cams, changed the TQ to a PTC 3500, replaced the gears to 3.55 SG, Went with a QF 650 DP (called and gave them the exact engine diameters) and junked that Eleb performer for an air gap! It was like day and night. No doubt that I'm in the high 12's or low 13's now. I'm currently in the process of having a set of RHS LAX stage 1 heads being worked at SD, they will be in later next week and my cfm will be dramatically increased. I'm not a fan of strokers, yes a 416 would kick *** but its also expensive. Anyway, thats what I have going on, your 360 is basically the same, bigger bearings, stroke but willl also kick *** if done right.

 

[POPS6T6]

This is a little more rough than it needs to be. If you're running KB107s, and you're running factory heads of some sort, you will generally end up with a static comptression between 9 and 9.8:1. Unless you blueprint the block and heads and are careful about head gasket choice you won't reach 10:1. "Blueprinting" means taking care to machine the parts down to what the factory said they were supposed to be. Normally the block surfaces are "tall", and the head chambers are "large" compared to what published specs. If you have a valve job done and keep the valves, the chambers get even bigger. So - really it's not a big deal. The only question is do you need vacuum for power assist brakes? If you have power brakes, look at a cam around 225-230° @ .050. So of the three you posted - #1 (XE274H) is too large for power brakes but a decent 360 cam if you don't need vacuum for brakes. #2 (XE268H) is the largest one I'd use and the best "all around". I've used many of them and they run great. #3 will work but IMO you're leaving a little on the table in terms of performance.
With what you should end up with for static non of these cams should have too much cylinder pressure so they are all pump gas, which octane will depend on your tuning and the fuel you can buy locally.

Moper,
Thank you for getting right to the point and keeping it simple for me! That helped tremendously and after reading all this I was now leaning towards #2 due to the fact that I didn't want to large of a cam. Forgive me if I am wrong, but doesn't it make sense for someone who is just building a reliable yet kind of "perky" engine to know the general cam and build the engine to match it? Now since I know the cam, i would know I wouldn't need to zero deck this block but would need to machine the block to ensure it is level and perhaps tighten up the chambers correct? Also I will be running disc brakes with a brake booster on it as well.