Best Cam Upgrade for stock 360???

SC397 wrote: Sounds to me like it is close to the Comp268H and Isky 270HL Comp 268H Advertised duration: 268 intake/268 exhaust Duration at .050 in. cam lift: 218 intake/218 exhaust Gross valve lift: .456 in. intake/.456 in. exhaust Lobe separation: 110 degrees Basic rpm range: 1,500 to 5,500 Good low end torque. Broad powerband. Excellent for towing or performance.  Slightly rough idle. Recommended compression ratio: 8:1 to 9.5:1 ISKY - CAM ONLY Good All-Around performance. Fair idle. stock Converter. 370-411 Axle Ratio. Up to 650 CFM Carb. 9.51 Compr. RPM-Range (2000-6000) Valve Lift (.475 .475) Valve Lash hot (.000 .000) ADV. Duration (270 270) .050 Duration (216 216) LC 109

 I have this in my 71 stock HC 360 works and sounds great . but remember change dist curve and intake as well . 

All this talk about cams,my question is what do you need to do to the heads to make them work.I'm told you have to have the heads machined to get thing to work righr as far as springs go ????

Just keep in mind that Comp Cams is not the expert on your engine.  YOU figure out which valve springs and push rods you need and order them accordingly. YOU measure what the base circle is vs the lobe lift is and YOU figure out what the push rod length should be.  Then tell them what you want.

Generally a bigger cam will need heavier valve springs for optimum performance, mostly to avoid floating the valves at higher RPM. Your cam should come with a recommended spring pressure, bot closed and open or a recommended set of springs.

Stock left vs upgraded right:



Things to look out for are piston to valve clearance, which can become an issue with larger lifts and/or duration, retainer to guide (valve stem seal) clearance and also any sot of binding or the rockers or springs.

Aftermarket retainers (right) can also help with retainer to guide clearance, otherwise you can machine down the guides and use different valve stem seals:



You can buy the Comp cams as a kit that will include matching springs, retainers and locks and even a timing set if needed.

The springs I posted above come from Comp Cams (926-16) fit the stock heads just fine and are specified for most of the Comp Cams in the performance range we are talking about here. Pushrod length should always be checked with any cam change because once you stray from stock, nothing is guaranteed. Converting to an adjustable valve train is also a good idea, but not essential.