[Rory McNeil]

I have not done any modifications on my 99 V10 2 valve yet, but I have also heard good things about 5 Star. However, as I understand it, most of their improvements revolve around changes made to the automatic transmissions reprogramming. Since my F350 is a 5 speed manual, that is not a consideration . My V10s exhaust manifolds look pretty restrictive, as does the exhaust Y pipe, but after hearing about the problems with the studs snapping off in the cylinder heads, not sure I want to try unbolting the exhaust manifolds to install headers. Supposedly the 2000 & newer 2 valve V10 heads are better than the earlier castings, but looks like a major job to change, and I have heard that the intake manifolds are different as well. No idea if the chamber volumes and shapes are compatible between early & late 2V engines.