building 273..or not

The 2 bbl motors had flat tops with 4 valve notches and about 9:1 comp. The 4 barrel motors had domed piston with 10.5 comp. The HiPo's also had a slightly larger cam that was a solid lifter cam.The 1969 motor that you have is Low comp. and has the hydraulic cam so if you want performance your going to start at square one.The early 4 barrel HiPo manifold you have more than likely has a different bolt angle than your motor but the Holley street dominator intake is almost identicle to the old 273 HiPo with the later bolt angle and they are considerably lighter.Your 1969 heads are probably the open chamber versions (like 318's). The early HiPo heads with the odd bolt angle were a closed chamber design.Just a few of the differences to keep in mind.