80’s 318 compression ratio figuring out where I’m at.

Putting in the KB167's will drop bobweight by around 90 grams.... balance with be quite far off of stock.... no dice roll necessary as the answer is known. The only simple way to get back towards balance is to find a good used set of 273 piston pins (205-210 grams each) and put those in with the KB's' they are about 75 grams heavier than the 132 gram KB pins and will put the balance back close to stock. Otherwise, you can use a nominal bobweight number on the heavy 318 rods with the KB's and use that to re-balance the crank only (cuts balance cost by more than half), and you will be pretty close on balance (as good or better than factory). I have the data if you want to go down that road; ask here or PM me.

BTW, if you have 4 small eyebrows on your stock-replacement pistons, then those are around 3 cc's, not 6.

Gearhed73 said

This all sounds very familiar to my current 318. Was basically trying to do the exact same thing. I ended up with a .040 over 318, pistons .090 in the hole. I picked up a set of 302 casting heads (measured at 60cc). I used the thin steel shim head gasket. After some research I ordered up the comp XE262 cam. Last time I checked my cylinder pressure was in the mid-high 140's.. nothing to write home about. However, with a 2800 stall and 3:73 gears its alot of fun to rip around in. If I could back it up, I would have swapped pistons, but I was tight on cash and wanted to get back on the road.

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You did quite well with that combination to get those cylinder pressures with those pistons. Good work.