I'm looking at an L31 which currently has the stock cam (.414/.428 191/196 111, 9.4 compression). Since the engine isn't in the car yet, I figure now is the time for a camshaft swap. Knowing the lift limitations on stock vortec heads, I'm considering a COMP Cams 08-500-8 (.480/.488 206/212 112) with the alexsparts spring and retainer kit (p/n Vsk4h53). Since I'm running a WC T5, my power goals are pretty moderate - 300HP and 350ft/lbs at the crank. I'm also using a FiTech EFI setup, so I need a reasonable amount of vacuum to keep that happy.

Any thoughts or recommendations? Anything else I should look at changing (aside from the timing cover)?

Thanks in advance!

 

GM 94666492. Listed for like $100 you cant beat this deal for a mild roller cam.

 

Thanks for the quick reply. That's a damn good price too, much better than the $289 for the COMP cam.

Looks like the 94666492 is .450/.465 205/212 112 based on this thread (although this thread claims it's identical to a Crane 104224 at .452/.465 214/220 112), would you be able to confirm? I see the listing for the cam itself, but I'm not seeing the full specs listed on that site. There seems to be a lot of argument and conflicting information here.

Or am I overthinking this for a mild cam upgrade?

 

How much power would you expect to gain with this cam??

 

https://www.summitracing.com/parts/c...make/chevrolet

Pretty similar to the lt4 hot cam, but less money than those go for these day and a little more lift. It will work with the alexparts spring kit.

 

This engine supposedly puts out 255HP and 320 ft/lbs in a truck with its current cam, so I'm hoping to hit about 300HP and 350 ft/lbs with a cam swap (45 HP, 30 ft/lbs).

Am I way off base here?

 

Thanks for this suggestion! However, wouldn't I have to worry about the press-in rocker studs with lift like that? My understanding was that over about .475" of lift increases the risk of pulling a stud out.

 

Sorry I did not think about that. I don't know where the threshold lies, but it probably isn't a bad idea to put screw in studs in or pin those ones if you plan to have some fun. I had a hell of a fight when I pulled mine out.

 

No worries! I'm just trying to be realistic with my power goals since the T5 is the current weak link, and avoid sinking too much money into the motor when I should be saving for a T56 swap.

I'm still strongly considering the 94666492 camshaft dmccain recommended earlier. That price is hard to beat and it looks like a solid upgrade over the cam currently in the engine. Anyone else have any thoughts?

 

I'm also on the fence about changing the cam in my L31 before I put it in the car. Realistically, at my age (54) I'm not much into going fast on the street like I was when I was 26 and had a bright red 87 IROC 350 car... so I waver between changing it, and leaving it well enough alone.
One factor to consider, the spring/retainer kit sold by ALex is currently out of stock..

 

People have reported 290+ out of the L31 when used with a better intake and exhaust. The 255 number assumes the stock truck intake/fuel system and exhaust, neither of which could be considered anything approaching performance parts. You might not need a cam at all.

 

Call Chris Straub, as I understand it hes his supplier anyways.
straub technologies . com

 

The ports are slightly better versions of the LT1 ports. So the fact that they only rated it at 255hp is a function of the intake, exhaust, and cam. The potential is there to make significantly more.

Even a mild cam combined with a good intake/exhaust setup will easily let it break 300hp, probably closer to 330-350hp.

The L31 is for all intents and purposes a Gen1 LT1 with iron heads. Stick a Stealth Ram on it and watch it go.

 

Thanks for all the feedback! I'm going to go with the 94666492, for the price and given my goals it seems like a no-brainer. If I can break 300hp with my current exhaust (Hooker 2055s and y-pipe, 3" into cat, single inlet/outlet 3" no-name muffler), intake (FiTech Go Street 400), and a $100 cam, I'll be happy.

Also, thanks for the tip on contacting Chris Straub. Not in a hurry as I can't start serious work until April, but if they're still out of stock at that time I'll give him a call.

Good to know that 255 number is a lowball figure too. I sort of assumed the truck intake/exhaust wouldn't be that restrictive, but it's nice to know I'm wrong about that!

 

You should be all over 300 with that setup.

 

That's what I was hoping to hear! Thanks again for the cam suggestion.

 

BIRD, I'm in the same boat, at age 53. I installed a new GM L31 in my daily driver Firebird about 4 years ago. Stock long block. All I did was install an air gap intake, HEI, Edelbrock 600 carb and long tube headers with true dual exhaust. It runs a lot better than I thought it would. Once it has a chance to breathe, it is more than 255 hp. Sometimes I think about swapping in an LT4 Hot Cam, springs, etc. Then the little voice in my head says to leave it alone and just drive it the way it is.