Without touching the short block (milling the deck or installing taller pistons) the best way to increase compression is to have the heads milled. Do you know what your static compression ratio is now? Did you check the chamber size of your current 906 heads? How far are your pistons in the hole? What is more important than compression ratio is having the correct quench area (.040" to .050") as this really helps eliminate predetenation problems. All the aluminum heads are designed for that quech area.
IMO, you can't just through parts on an engine and expect it to work perfectly the way you want it to. You need to design the entire engine for what you want to do from the start. That being said, Chryco Physco said if you gave him more details about your current engine, he could recommend a camshaft. He's got an excellent reputation here and has obviously "been there and done that".
I understand that, this is the engine details that i know of, i cant gurante that it is the same camshaft because when i bought the car the engine was kinda fresh rebuilt because something happend with the engine with the previous owner.
I got a book with the car and then the engine specs is:
440 drilled 0.60
Edelbrock performer RPM
Quick fuel 850
906 heads (intake valves 2,08) (exhaust valves 1.74)
Camshaft mopar performance with 0,509 lift and 292 degrees duration (c:a 242 at 0,005)
Dubbleroller from mancini racing
TRW forged sixpack pistons with 9,7:1 in compression.
This is what the book says it is in my engine. I think its to ”tame” , the car is a 4 speed with 3.55 in the rear. Iam planing to change to a 3.91.
So what is my best options if i want more horsepower?