340 w/ 650 double pumper ?

I've always heard a 69 340 with a 650 double pumper performs very well. I've had a thermoquad that when it's tuned right it really moves when I get into the secondaries, but the car mostly sits all year then that thermoquad starts acting up. I've now got a Holley 600 on it now & seams to start real easy & run pretty well but was wondering about the double pumper . I've got the LD340 intake & a 68 Formula s cam & 3:91 gears , stock 10.5 pistons . Any thoughts ??