In my search for more power I'm digging through all the parts I've collected and stumbled across a brand new crane powermax 272-2 with new lifters. Is this drastically too big for my lg4 5spd car?

 

Probably. Not a bad cam, but will want more compression than what you have, to avoid the soggy feeling at low RPMs. It will run pretty good at higher RPM if your LG4 is modified for better breathing (exhaust above all else) but in a totally stock one it will probably feel like you have lost A BUNCH of "leave". Works better in a L69.

 

I ran an old K1104 on an LG4 and it done pretty decent.

 

I guess I should have included my plans besides just the cam. My car already has the dual snorkel l69 air cleaner, will soon have headers and full exhaust. Is my stock compression ratio not 9.5:1?

 

Also, is this too much lift for uncut stock heads?
​​​​​​

 

I can only vouch for up to .450 lift on stock heads definitively - i dont know how much more they can handle

springs and retainer replacements should be mandatory

 

LG4 compression ratio is 8.6:1, L69 is 9.5:1.
That is a lot of valve lift for uncut heads, you MUST measure. Alex's parts has a kit for that without machining.
https://www.alexsparts.com/valve-spr...ssure-vsk4h50/
https://www.alexsparts.com/valve-spr...ssure-vsk4h52/
https://www.alexsparts.com/valve-spring-kit-sb-chevy-vortec-hi-perf-hyd-roller-130-lbs-seat-pressure-vsk4h53/

 

If my engine is less than 9:1 compression I'm going to skip the cam idea altogether and just start putting together a 350 shortblock. Will probably just do headers and 1.6 roller rockers until I'm ready for the swap

 

Best thing you can do man. 350

 

A good cam choice for a 8.5:1 cr supercharged 305.
A good cam for a high compression 305 10:1+
Say with improved/ported heads and headers

Can be enhanced using 1.6 intake rockers to increase intake valve lift. X 1.0666
The Edelbrock EForce supercharger does sick things to a low cr 305..

 

I guess I should update this thread with what I have found out about my engine since this thread started. Block casting number is 14010207 and both heads are casting number 462624 so it is most like an early 80s 350 and not an lg4. I still plan to use the crane 272-2 cam, but I have picked up a set of vortec 062 heads and a jegs vortec intake for it. Hoping it will get close to 350hp

 

Will work very well with vortecs.
Will need spring upgrade and valve guide boss machining for lift clearance.
Use a
.015" shim head gasket.
If the 350 has flat tops ,,bonus points.
370-375 hp. 750 carb hi rise RPM style intake
1.6's on intake only

 

Right now I'm still on the fence between using Alex's .550 spring kit or going with beehives. From what I can tell with my little USB camera, it has normal sbc 4 eyebrow dished Pistons. From what I have calculated, the steel shim style head gaskets should bring it to right around 9.5:1 compression. For right now, i will stick with the 600cfm holley that I just put on it. Might look to upgrade that later as the budget allows.

 

To consider the beehive springs, for starters, you have to look at the installed height and valve open pressures to see if they will work well with your cam.
Then there is the issue of fitting them into the spring pockets in the heads - machining required???
The Alex kit will get you there with NO MACHINING and waaaaay cheaper.