Doing a complete overhaul on a LG4 305H, and have the comp cams part# 12-205-2 cam in mind. It has .425 intake and exhaust lift. 252 duration. Is this too much cam for a stock 305 with computer still in use. The cam i had before was the crane cams 114102 .378 and .401 lifts, and i really liked it. It worked well with the computer controled carb. All parts in motor are bone stock, .030 over on the pistons and supercomp 2055 hooker headers. I dont know how big of cam you can go with still using the computer, without it idling too rough.thanks for any advice.

 

That cam should work just fine, you probably wont notice any difference in idle or gas mileage, but you will see a little extra umph. As long as you dont get anything to radical most mild cams under .470 lift or so will work fine with the stock cpu. I know people using the XE262 cam with the stock cc qjet and chip without any cpu or drivability probs. I would look into the XE256. I have it in my 350 and I like it. I wish I would have gone with the XE262 for a little more hp,but this cam has a ton of off idle torque and idles nice and smoothe.It would be great in a 305 with a full exhuast. Good Luck.

 

I'd go with the XE256H 12-256-4 212/218 .449/.456

It has more agressive ramp rates for more power.

 

look up the Xe256. I am using that in my LG4 in my caprice. Factory converter, factory crappy rear gears. Works fine. Has a SLIGHT lope to it, draws plenty of vacuum. Take a look at that to get an idea of the specs.

*edit* damn...3 votes for Xe256 in 3 minutes....hmmm perhaps its a decent 305 cam.

 

I said it first

 

Yeah you beat me by a minute because i had to take a ****!

 

Some things don't need to be said, ME Leigh...make up an excuse...you had to water the toilet, or something like that.

 

lol

Ok i had to let the dog out.

 

Here's my "dog" http://store.summitracing.com/partde...4142&view=1024

For the record: Idles smooth at 500 RPMs in gear, revs easily to 5500, have had it to 6300 RPMs on several occasions (due to tranny "issues", it won't shift 2-3 at WOT - so, at the track, shifting at 5500 it goes through the traps in 2nd at 6200), easily passes emissions testing (full visual, enhanced dyno type). If the tranny was fixed, and I had better gears, I'd want at least 3000 stall for best ET's since power really starts to come on at 3000 RPMs. The stall I've got is fine for "normal" everyday driving.

Lift isn't a factor with the computer as much as overlap. Keep the duration reasonable and LSA "high", and the computer couldn't care less. The computerized carbs aren't nearly as sensitive to these things as EFI is.

How much are you willing to change/modify? What is your intended primary use? Are you willing to sacrifice a little MPG for better ET?

What you must do: 1) Valve springs. The stock ones floated at 5200 for me. Don't skimp here. While you're at it, have the guides cut for positive-type seals. Make sure you have adequate retainer to guide/seal clearance for the cam you choose. Stock heads/springs are often good for only .45" lift or so. 2) Air cleaner. That stock single snorkel thing is embarrassing.

What you should consider: 1.94" intake valves, porting work (at least pocket port, or bowl work, as it's sometimes called).

Don't forget: Keep things "matched". Cam, intake manifold, and torque converter need to work together.