What elevation are you at?
From the catalog:
The cam P5249663, is a 250/264/110/ .385/.401 lift roller cam,very similar intake duration to the stock 360 cam.
The heads are supposed to be P5007086 swirlport Magnums at 60cc/190cfm, 1.92-1.62valves
The block is P5007549 and with those heads is spec'd to come in at 9.1 Scr
The power curve is almost dead flat from 4000 to 5000, and beyond. The torque curve is a big fat bump from 3500 to 4000; 5900 is as good a shift-point as any.
It is spec'd at 300/375;
In an A-body with a 2600TC and 4.10s, it should run like the proverbial scalded cat
At a 2600 stall, that engine is probably putting out around 285 ftlbs. With your 4.10s and 27s that would be;
285# x 2.45x4.10x12/13.5=2550 road footpounds corrected to a 12" radius. 2000# is more than enough to spin 295s,both of them. You will need a double pumper tho to control it cuz with a VS the secondaries will not stay open if you back off the throttle; and that just kills drifting.That engine wants a 750,(Will run very well still,with a 650 mechanical secondary)and a spreadbore would be ideal. With only 37* of cam overlap,that spreadbore could make pretty good fuel mileage, despite the 4.10s.
BTW that is not a low compression engine. I mean the 9.1Scr number might be, but the Dcr is right up there with cylinder pressure almost maxed out, for the best gas. Do a compression test; I bet it will be close to/over 160psi, at sealevel. If it isn't, that might be part of your problem. What elevation are you at?
With closed chamber heads and tightQ, you should be able to run close to 36* with 93. However, on the street your butt-dyno will not be able to tell 2 or 3 degrees from optimum, but your engine will complain about just one degree too much. Point is, sneak up on it. Fatten up the timing from stall to 3000 instead.
Edit, Ok so no tight-Q on this one, My math puts the pistons about .060 down. So 32 to 34 will be pushing it, as mentioned by others.
_________________________________________
My engine was once dressed similar to yours but with just 3.55s and a 4-speed. It was hands down my favorite combo.
Whenever I suspect low-power, the first thing I do is check the pressure. You can spend all week tuning, but if the pressure is down, you get to fix that and start all over.
_________________________________________
if you want more power; spec wise,that engine is ready for a little more cam. But then it might want more TC too,lol.
And a higher shift rpm, and so a teardown to perform the oiling mods necessary to survive multiple blasts past 6000.
Of course since it's all tore down, now would be the time to zero-deck it.
Of course since now she has potential, the next logical thing to do would be to put aluminum heads on it and drive the cylinder pressure up past 185psi, and;
finally you have the engine of your dreams, able to spin street tires to 80/90mph, whoopee! Welcome to HotRodding.
What elevation are you at? Did I ask that already,lol? I think you might be at 500ft or less, so I guess global warming doesn't excite you much,lol.
At 9.1Scr, the Wallace calculator puts you at 160psi/150VP@500ft, This should be very strong below 3000
