I have a 1990 5.7L, automatic with ported edelbrock intake, ported slp runners, edelbrock headers, 24lb injectors, 58mm throttle body, with gmpp fast burn heads, I am looking for the biggest cam I can put in it and still pass the CA SNIFFER TEST, im willing to swap out torque converter and tune just to pass sniffer test...thanks in advance

 

I passed with to comp xfi 268

 

I passed with a comp cams xfi 268 cam

 

Thats the cam I am leaning towards but im not sure on how to increase maximum valve lift on the fast burn heads to accommodate for the xfi268

 

Isn't the lift only .357/.354 ?

 

Lobe lift. With a 1.5 rocker its .535/.531

 

Ah ha, lt4 springs should work but I'm sure the guides need to be cut down.
Or 26918

 

I would typically run abit more spring with that cam depending on the intake manifold. With tpi it wont go much over 4800-5000 so you can get away with bit less spring pressure. Hsr miniram i would stiffen up as cam will go to 6000 in a good headed 355. Lobes are pretty aggressive

 

No problems here with an xfi268.

 

Passed smog with xr276 hr comp cams and 1.6 roller rockers

 

I agree with the XFI268HR-113 camshaft. Its like an LT4 hot cam but better ramps and lift, plus the 113 LSA makes it easier to tune and pass smog.

The Manley 22407-16 springs will handle .600" lift, too.

 

Valencia1z, that's a fairly large cam with 224-int/230-ex duration at .050". You mind me asking what other mods you did and who did your tune?

 

Whats a good head match for the XFI268? Ca legal of course

 

On mods during that time AFR heads as&m runners big mouth base 58 mm throttle body SLP shorty headers stock 5.7 24 lbs injectors 10 -12 base timing total I'm pretty sure around 32 to 34 total on a 350 low compression during smog set at 6 or 8 air fuel was always good and ran a vigilante 3200 gears 3.23 car was good for mid 12.s on motor on a mickey Thompson drag radials mid 11s spraying