Styled Allis WC stroked?

Im going to try building a Allis WC for pulling and farm use. I was gonna put in a wd 45 crank, stock rods and slight cam work with flat top pistons but when i do the math I get  15 : 1 compression. I may have the math wrong but anyone got any advice to bring it down so i can still run pump gas and start it from the stock starter. Or any advice to get more power out of it. 

I put a WD 45 crank in a 1948 WC. I used WC rods and WC aluminum flat top pistons. I did extensive static compression ratio calculations. The CR calculates to just a touch under 8:1. The head has a quality valve job with ports cleaned up and seats blended into the bowl area. It'a a 12V conversion with stock 6V starter with the improved starter drive. I run a distributor with Pertronix electronic conversion with slightly heavier mechanical advance springs which is year round in Northern New England. This stretches out the advance curve to avoid ping at extreme low RPM. It runs fine on regular gas for regular chores. When I tractor pull which is rare, I run premium gas. It really wakes up a WC. I believe it gets over 50 HP. Makes the WC a lot more fun. I'd do it again in a heart beat.

Yes I'm running a stock Carb, Manifold, and Cam. A bigger carb from a D17 would help at higher RPM like when pulling a transfer sled in competition. A pulling cam would also help also, but specify to your cam grinder whether your pulling a dead sled or a transfer sled. I run a 35" overall length, 2" or 2.25" inlet and outlet glass pack muffler with a flange welded to the top of the manifold and muffler inlet. This eliminates the restrictive pipe fitted inside the exhaust manifold.  I also installed a flapper cap on top and painted the whole exhaust system Rustoleum Barbecue Black. I found it holds up better than Krylon. It sounds great and not ridiculously loud like open stack. I still wear head phones when mowing with a 6' finish mower, mostly because of the mower noise. Plowing snow etc., I find I don't need the head phones.