I can't find any information on old forum posts, so I want to know if the compression ratio is about the same on Giant Power head as a regular Ford low head? Visually, it appears like it would be about the same. It also looks like it will use the standard high head bolt, in fact it looks like maybe it will go into the block 1/8" further.
On another note, while going through my used head bolts, I noticed a number of head bolts are countersunk in the center slightly. Was this a cost cutting measure?
I believe the Giant was the same as the Haibe which is 4.3.
The 9-10 low head is 4.2, the rest of the low heads are 4.0.
Go to the link below for the Tulsa Chapter dyno testing with various heads:
Hope that helps...
I am running a Giant Power head on our 13 touring. It performs better compared to the original low head. The Z head has higher compression. The compression chamber for both Giant an W.R. heads looked the same to me. The Giant and W.R. heads have the horse shoe style combustion chamber like the Z head. The valve pockets for the Z head is not as deep compared to Giant Power & W.R. heads.
The Giant Power head increased height will interfere with the stock 13 fire wall.
Simmons Super Power head, same chamber. No problem with 26-27 fordor firewall.