TBI-fed L31 Cam Recommendations

[Fast355]

GM 12677151

215/223 @ 0.050
0.473/0.473" lift
108 LSA
109 ICL

It comes from GM in the SPO 357 HP 350.

Its basically a L31 with a marine 0.051" compressed head gasket that drops compression to 9:1 and a cam change.

Friend of mine had one put into a 4 bolt main L31, broken in and dyno tuned on an engine dyno. 385 hp @ 5,600 and 422 tq @ 4,000 with a performer rpm intake, a 650 vacuum secondary holley and 1 5/8" long tube headers. It made 400 ft/lbs at 2,500 rpm. Pulled 16 in/hg vacuum at 650 rpm.

I had one in my Express van with head work, thorley tri-ys and a looser than stock converter in the 4L85E. It had great manners and made good power.

I have tuned way bigger cams with the stock later TBI computer but it is up to you and your experience tuning to make it run right. A stock L31 is a big enough chore for a first time tuner.