318 Build

And just running some combinations for SCR/DCR all with the pistons .077" in the hole, 6 cc eyebrows total and .028" head gasket:

1. Stock cammed 318 as above with 675 type 318 heads: SCR/DCR = 7.8/6.8

2. Put on 308 heads milled to 62 cc chambers and assume a 284 cam is what the OP has with 110 LSA and advance it a small gob of degrees to 102 ICL :
SCR/DCR = 8.3/6.6.... so not too awfully bad a DCR drop from stock but still a bit less low RPM torque than a stock 318

3. Put in a 268 cam in (somewhere around 215 to 220 duration @ .050") and 110 LSA and installed a 104 ICL:
SCR/DCR = 8.3/6.9..... hey, now we are back to stock 318 low RPM torque-land and of course the top end is gonna be lightyears better.

4. If we COULD mill those 308's to 53 cc chambers, and stick with the 268 cam as above.
SCR/DCR = 9.1/7.6.... hey, now things are better all over low and high end.

5. For laughs, let's compute my overcammed low compression Opel 1.9L from when I was coming up this learning curve 30+ years ago, with the 300 advertised Isky cam and 7.6 SCR:
SCR/DCR = 7.55/5.32.... WHOA, the Wright Brothers had better DCR at Kitty Hawk in 1903 LOL.

No wonder that thing was totally DEAD below 3800 RPM! It was kinda usable for racing since that engine could stand revving to 8k all day long, but you can't get away with that on a stock 318 bottom end. I woulda had a much wider usable torque band (larger ratio of good low to high end torque RPM's), and thus I'da been a lot better off racing-wise, by dropping the cam duration 20 degrees or a bit more.