TTA vs GN Head & Piston Dish Volume


New Member
Anyone know the piston dish volume for the TTA? From searching I found a post that the TTA heads are 41 cc's. The JE Catolog lists its forged GN replacement pistons as having a 29.5 cc dish with a 48 cc head volume. If these are correct, and all things being equal then the TTA piston dish would be 36.5 cc in order to get 8.5:1. Just wondering if anyone has actually bothered to measure?