The more load there is on an engine, the less aggressive the ignition timing curve can be before spark knock occurs. With that being said gp's are very heavy and have very low final gear ratios. Id imagine this puts a lot of load on the engine, limiting timing advance. With 3.69's engine load would be reduced,in theory allowing more timing advance before spark knock. Can anyone with 3.69's support or disprove my theory? I'm not trying to justify 3.69's over headers or anything just want some info.