theno1prince

iTrader: (1)

I'm building a 350 for my car and can't decide on a cam. I already have a 260xfi from a previous build that never happened (I was going to sell it, but now I'm wondering if I should just use it). However, I keep looking at the 268xfi. I know a lot of people run the 268xfi, but I'm not sure if it would be "the right cam" for me so I keep flip flopping between the two (or should I look at something else?).

The car is going to be used as a daily driver so gas mileage is obviously a concern. I do want this car to be fun though. I really don't see myself doing a cam swap once the engine is in the car, so I want to get it right the first time. I'm really hoping for around 350fwhp.

The engine is just a stock shortblock 350 bored .060 over with full dish pistons (12cc). The heads are 195cc, no name brand (Renegade I think?) vortec style aluminum heads with 64cc chambers and 2.02/1.6 valves.

The flow numbers that were given to me for the heads are:

Lift Int Ex
.200 114.3 92.7
.300 163.3 124.0
.400 207.7 150.4
.500 243.2 171.0
.600 265.8 173.6

Compression should be around 9.3:1 (piston to deck clearance is ridiculous on this thing). I will be running 1.6 roller rockers and fueling will be via TBI (50mm bores, 90lbs injectors, afpr). I haven't decided for sure on the intake. I have a GMPP TBI intake which I will probably use if I go for the smaller cam. I might go for a Performer RPM manifold with adapter if I go bigger on the cam.

I'm also going to go with a 2000 stall converter (depending on the cam, maybe a 2500) and I will be swapping the rear out with 3.42s.

Opinions?

86LG4Bird

iTrader: (1)

Definitely stick with the smaller cam for that low compression and the mild torque converter options you're considering.

theno1prince

iTrader: (1)

Kinda what I was thinking. It's just hard to fight that itch for bigger. Think I should still be able to hit my horespower goal of 350fwhp? Any other thoughts?

86LG4Bird

iTrader: (1)

Probably not 350 fwhp. But... attempting to get there by going with a mismatched cam will only result in an all-around lower performing engine, less average hp in the useable rpm range.

theno1prince

iTrader: (1)

Hmm...good point. Any ideas how to get to my goal? I could get the block decked to raise the compression (should move it up around 9.7) but I don't know if it would be worth the cost/trouble considering what's in the bottom end. I'm trying to get this thing finished within a month too.

redneckjoe

what about useing a 0.015 compressed head gasket?

theno1prince

iTrader: (1)

That's what I was planning on using. The piston to deck clearance is ridiculous on this block. Like .045". I checked it using a straight edge and feeler gauges. So with a .015" gasket that's still .060"!

theno1prince

iTrader: (1)

I'm probably asking the wrong question. I should be asking what would I be happiest with given the combination and intended purpose (daily driver). Should I just slap together what I have? Should I pay to get the deck blocked and run the 260xfi? Or should I have it blocked and run the 268xfi? I'm not trying to spend a ton of $$$ on this thing but is a .4 increase in compresson (from 9.3 to 9.7) really going to make a big difference?