Thread: I'm Sure You're Tired of Answering Q's on this Subject,...

Tweet

but I have decided what all of the other parts I am going to use, so I must ask the dreaded question, what cam should I use? I will make it easy on you and give you all of the information you need to know:

Ok, so I've decided on the bottom end of my block, now it's time for the cam. I'll be running a zero decked 350 with 9.5:1 compression and vortec (as the come from GM because I can't afford head work, I may clean up casting flash in the ports and even out combustion chambers) heads with 1.5 ratio rockers. This is a truck motor, so it needs to have oodles of low end torque and be able to run California 91 octane. I would like to run 89, and I think with the right level of tuning I will be able to, but I am going to be realistic and say 91. I was originally thinking something with not much more lift than stock and not much more duration, but after hearing about Rhodes lifters and Crane's version which I have forgotten the name, I think I'll give them a try. They bleed off pressure below 3500 rpm to, in effect, shorten the duration of a cam. Using these lifters, what is the biggest cam I'll be able to run and still pull enough vacuum to run my power brakes and still get decent gas milage (my other goal of having this engine is to get better fuel economy than stock, hence the higher compression ratio). I don't want to run much more than 1200 or 1500 rpm stall, and I don't mind a lopey idle. I hope this is enough information. Cruising rpm is going to be around 3000 rpm plus or minus a few hundred.

I think this should be enough information to make a cam selection.