I always used to be REAL conservative when choosing street cams.Never made the power I wanted either.Always ended up building real torquey motors that wouldn't pull past 5000 rpm at all.I don't know what head your are running but you said the intake is oval.With that many cubic inches and oval ports,I don't think you should have any problems making some good low rpm power.As far as a cam,the cam I got in my car now is a Comp solid roller 308AR.It is a 652 lift cam with 308 adv dur and I think the .050 is 260 something.My car weighs right at 3400 lbs with me in it.I was running 4.88 gears on a 28x9 slick with 11.2 comp and a 3800 stall.When I got that cam I thought I had bought a monster race piece.I had never ran more than a 575 lift at that time.Found out that my "monster " cam,a cam I thought would kill bottom end on the street,is what I had been wanting all along.Personally,I belive that a 650+ lift cam with 260+ duration is a great place to start for a STRONG street cam.It's pretty rough for a daily driver,but for the occasoinal burn the streets up,I love it.Pulls HARD from 3000 all the way to 7000 rpm's.Don't be scared to go big!!!But it all really depends on how radical you want it and how much you plan on driving it.But don't be scared that alot of duration might kill your bottom end.It's all different with a roller
P.S. My car runs on 93 octane with a little 110 mixed in(4 gallons of 93+1 gallon of 110) your 10.5 should be fine for pump gas.And the 750 dp,I run a Dominator.the motor uses up everything my 1050 can throw at it.Actually I was having to jet it down so I could hook on my baby slix.