whats my compression

i just got a 1966 lemans with a 400. the block is a  stock yh 1974 block with a lumpy cam and the heads on it is marked #13. will i have the 1970 compression ratio with the 1970 heads?i don't know what head gasket he used when he put it together. i just want an estimate is it close to 10-1? the info i found is that the stock 74 heads had 175 or 190 cc and the 1970 #13 heads had 72 cc. any help?  

On a 400 with flat top pistons and 72cc chamber heads the CR will be around 10-10.3:1CR.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

thanks when i got the car i asked the guy if he remembered what cam he put in it, he was going to try to look up his paper work. it has headers and an intake. the car has a 700 r with 4.10 gears runs great and sounds great with the lumpy cam.body needs work can't wait to take it to the track. do you have any idea of the weight of a 66 lemans? thanks for the onfo.  

My 65 with after market air is 3550 with half tank of gas. Comp Cams web sight has a calculator for compression just Google compression calculator. You will need basic motor details and the intake closing from the cam card or degree it yourself to find it and it comes right up. I was surprised how low mine is with the 6X-8 (105cc)heads on a 400 with good pistons. It was like 8.15 static and 7.2 effective, guess I don't need any octane booster for this combo. These motors must have been a real go getters with the early heads and 100 plus octane gas. Next on my wish list is a set of 85cc heads still only calcs to around 10 to 1. Just ran another calc from a different site and it comes back with 8.7 static so maybe I did the first one wrong but that sounds more like it.