I am rebuilding my motor and am getting a cam. But I want something that will give me gains, but will keep the SD system happy. What should I look at. Also, the block will be 350 but the heads will be 305.

 

Probably the production LT4 cam.

 

just curious how big is that cam and were can you find it?

 

idk, a good tune should keep the SD system happy with most any cam... i'm not sure how big u could go without needing a tune. probly not too big. else u wont be seein the gains the cam is capable of.

 

SD is not very tolerant of modifications on the stock chip, ask any TBI owner. Do yourself a favor and pick the right cam for your motor and gearing and have a chip burnt to match. Dont cop out on a nutless cam just because you dont want to burn a new chip.

this is one of those deals where us MAF guys have the last laugh. I have upgraded cam and heads and exhaust with the stock chip and I think my #s are pretty decent. the chassis dyno shows me fueling pretty accurately, although I could use more timing I am sure.

 

How do we find a good person to burn the chip though? I've been hunting around WI, and only found a place a few hundred miles away!

 

Time to buy some chip burning equip!

 

Robert, Im still pretty new at it but eventualy I will helping people out with this. If your interested shoot me a PM and we can figure something out.

 

with SD, you probably won't get away with very much change at all, maybe one step up in duration from your factory cam -- and this is only a guess. the post above regarding MAF is true, as fueling changes during partial throttle (ie, up to 80% TPS) are adjusted by the ECM on the fly; SD as you know has the fueling inputs hardwired into the lower fuel table in the chip. in this regard, the MAF guys have it all over us.

when i had my mods completed (with LPE 219 cam, which is 2 full steps up in duration), i had what i thought was a custom chip; the "tuner", who was big on this board about 2 years ago (whose name i won't mention), didn't make ANY fueling changes to the lower table in my chip (verifed by a .bin scan later), and consequently my engine detonated severely. my mistake for not verifying early on. no fuel = ultra lean detonation = top ring land failure. not a good thing.

you MUST have the chip recalibrated, even with mods such as exhaust (assuming long tube headers), on a SD setup. your ecm will not be able to compensate for the change in air/fuel ratio with SD, anywhere near what a MAF setup can.