I was looking through the new mail order parts book and noticed some camshafts. I was in the mustang section albeit, but reading the description, it showed some comp cams that advertised more top end power, throttle response and aggressive sound WITHOUT vacuum loss. Okay before everyone jumps on the noobie, I know trucks need bottom end, not top end. The cam is the comp 35-510-8 cam 1,300 - 5,300. Looks like a split duration cam with the greater values on the exhaust. I know SD depends on vacuum to work properly and what will work for a Mustang won't work for a truck. But I have noticed several other manufactures claiming the same, performance and sound without loss of vacuum. I would like to put a cam with a hint of lope in my 351 EFI SD. I like the sound the E303 cam makes at idle but is a gamble with SD and not the best power band (2,200 rpms). Is it possible to have a cam that is an improvement over the stock, have a good sound and still keep the SD computer happy?
And one more question on a subject thats always bugged me, how much will advancing cam timing shift the rpm range for said cam? Lets say the cam in this post since I know the Rpm range for it is 1,300 - 5,300. If I put that cam in my truck and advance the timing 4* (which what I read takes a little top end power and increases the low end) would that shift the rpm range down say to 1,000 rpm's?

 

A coulpe of phone calls to the cam grinders is your best bet. They will, or should have a whole list of questions about your truck and how you intend to use it. Be honest with them and your self and you should get the right cam for your needs. Good luck

 

Yes.. and the older the motor the more of an improvement you'll see because the early EFI cams were rediculously small. Spend some time searching around this forum, this question comes up A LOT so you'll see lots of suggestions.