TTop Tony

Can you use a marine version of a cam in a 350? I ask because I called Comp Cams and told them I have 3.7 gears and a manual transmission and needed more power up top but had to pass a sniffer test and they suggested
either an XE268 or a 270 magnum cam. Both of these cams are big and have a 110 lobe seperation but they have a marine version:
original xe268 268 280 224 230 .477 .480 110
marine xm270 270 286 226 236 .480 .489 112
Do you think that cam is too big to pass an idle test? Anybody using this cam?

PatG

I passed the TX smog test with the regular Magnum 270 last year but not by much. I think my HC number was around 340 ppm with a limit of 350. HC was the only problem area. You need to know what your cutoff limits are for your state. I know that TX not only started a dyno type smog check but also clamped the limits considerably (used to be 600 ppm). Also, I did nothing special for the test so I'm sure an oil change and a bit of carb tuning could bring the number into the 200s.

TTop Tony

Its 500 hc allowable and 5.0 co (I think thats it) in Nashville. I already lower the timeing, lean it out and boost the idle to 1000 rpm. I haven't failed yet but my cam is pretty tame. Not like these ones.

Smokehouse69

Sometimes Marine cams are reverse rotation. So, make sure it turns the right way before you put it in!

TTop Tony

Doh! I never heard of that, thanks Smokehouse69 I'm glad I asked. Maybe I'll call and ask comp cams and keep looking for now.