I have a 400ex that needs its engine gone through and built for flattrack/tt. Sparks has a year wait, who else can do the job?

 

You could try GT Thunder in ohio...

 

GT Thunder does good work, but what are you looking for? 406, 416, 426, 440? Sparks definately has the reputation, but they also have a huge waiting list. I've heard good things from Hetrick Racing, Tom Carlson, Sparks, FST, and the list goes on and on.

But what you need to figure out is how you want your motor built. The larger the bore, the less reliability is usually the cause. I have witnessed 398cc motors hurt 440's VERY badly in drags, repeatedly. Its not always about how big your piston is, but how well all your components work together.

If you were to keep your motor somewhat stock, I would recommend these mods, not neccessarily in this order. K&N filter, rejet, Sparks degree key(not recommneded for big bores), head work, port work, high comp. piston, pipe, etc. When you get all these mods and its still not enough, you might try some work on your stock carb. Take the choke out, have it taperbored, etc. A 400EX is pretty cheap to make fast.