Hi all. I'm in the process of rebuilding the Pontiac 400 out of my '78 Trans Am, and I'm kinda wondering which cam I should go with? This is/was a budget build, so I would like to use one of the cams that I have on hand already if possible. Specs are listed below, but I've got a Summit K2801, a Summit K2802, and a Crane Energizer 105082 (284 H12) available. As far as what my goal would be performance wise, well I don't feel the need for excessive power. Previously the engine dyno'd at 230 hp/300-ish tq at the wheels and had a best 1/4 of 14.25 (I'm not the best off-the-line). I'd like to do better than that, but I don't want to sacrifice streetability with an excessively high idle to keep vacuum levels up (I had idle set at 750-ish RPM with a Holley 650 before). If it's got a lope then great, but I'm not gonna choose on lope alone.
Car specs:
1978 W72 Trans Am. Original 400 engine, ST-10 4spd manual, 3.42 posi rear. I am in the process of swapping in a t56 6spd manual trans as well.
Engine specs:
W72 400 block (not the weaker 557 block), bored 60-over. Stock crank (turned 30/30) and rods, cast pistons, stock-style cast iron rings. Stock 6x-4 heads that I am in the process of cleaning up the ports/runners/bowls and will get a 3-angle valve job when finished. Screw-in BBC 7/16" studs with locks to replace stock non-adjustable studs. Stock springs, pushrods, and rockers. Stock 8.1-ish compression I believe.
Bolt-on's: Performer Pontiac aluminum intake with rebuild Q-jet. Tri-Y longtube headers into true dual 2.5" exhaust dumping after the axle.
Camshafts that I already have:
Summit K2801:
Int dur @ 0.050: 214, Ext dur @ 0.050: 224
Int lift w/1.5 rockers: 0.444", Ext lift w/1.5 rockers: 0.466
LSA: 112 deg. RPM range: 1,800 - 5,000
Summit K2802:
Int dur @ 0.050: 224, Ext dur @ 0.050: 234
Int lift w/1.5 rockers: 0.466", Ext lift w/1.5 rockers: 0.488"
LSA: 114 deg. RPM range: 2,200 - 5,500
Crane Cams Energizer 105082:
Int dur @ 0.050: 228, Ext dur @ 0.050: 228
Int lift w/1.5 rockers: 0.480", Ext lift w/1.5 rockers: 0.480"
LSA: 112. RPM range: 3,000 - 6,000
Thanks for any guidance you can offer!
Car specs:
1978 W72 Trans Am. Original 400 engine, ST-10 4spd manual, 3.42 posi rear. I am in the process of swapping in a t56 6spd manual trans as well.
Engine specs:
W72 400 block (not the weaker 557 block), bored 60-over. Stock crank (turned 30/30) and rods, cast pistons, stock-style cast iron rings. Stock 6x-4 heads that I am in the process of cleaning up the ports/runners/bowls and will get a 3-angle valve job when finished. Screw-in BBC 7/16" studs with locks to replace stock non-adjustable studs. Stock springs, pushrods, and rockers. Stock 8.1-ish compression I believe.
Bolt-on's: Performer Pontiac aluminum intake with rebuild Q-jet. Tri-Y longtube headers into true dual 2.5" exhaust dumping after the axle.
Camshafts that I already have:
Summit K2801:
Int dur @ 0.050: 214, Ext dur @ 0.050: 224
Int lift w/1.5 rockers: 0.444", Ext lift w/1.5 rockers: 0.466
LSA: 112 deg. RPM range: 1,800 - 5,000
Summit K2802:
Int dur @ 0.050: 224, Ext dur @ 0.050: 234
Int lift w/1.5 rockers: 0.466", Ext lift w/1.5 rockers: 0.488"
LSA: 114 deg. RPM range: 2,200 - 5,500
Crane Cams Energizer 105082:
Int dur @ 0.050: 228, Ext dur @ 0.050: 228
Int lift w/1.5 rockers: 0.480", Ext lift w/1.5 rockers: 0.480"
LSA: 112. RPM range: 3,000 - 6,000
Thanks for any guidance you can offer!