400ex Matching Exhaust Port to Header?

[Metzroth]

My friends bro who has rebuilt several motors said if I wanted he would match my exhaust to my header. Will this make a huge difference? He is going to do it for my new HMF that is OTW. After the exhaust and such I will have $150 left that I plan on spending on motor work. I want power only right now. I'm doing suspension b4 i race just that I already started power so I want to finish it. I know I can't afford to bore it out right now. So far with help of quite a few members (in another thread) I have decided to run a thinner head gasket and a film of threebond instead of a base gasket. So other than this what do you guys reccomend? Can I get a cam and the gaskets for $150? Instead of a cam should I advance the timing along with the thinner head gasket and a film of threebond on the base? I wanna do this right so if you could give me details on how to do whatever you think I should do I would appreciate it. -Metzroth

[cals400ex]

the cam and piston combo will do much more than advancing timing and other small add ons. you can get a hotcam for around $120 and the head gaskets from C&D are $20 if i remember correctly. just get a cam that suites your riding style. make sure your cylinder is honed out before you add the piston too.

port matching the pipe wouldn't hurt. don't expect a huge gain though.

[400exrider707]

Hotcams are about $100 on ebay, and you can get an entire tusk top end gasket kit for $15.

[boricua]

match porting usually improves flow from head into the pipe, less turbulence, and fewer hot spots on the exhuast. the gains are
minimal, but they are there. usually you wont notice too much of a horse power gain unless your exhaust pipe is way smaller than your exhaust port. the same goes for the intake...if the intake runner is way bigger than the intake port, then there is a step and some fuel may get caught in that step to be released later. it just simply flows better, in and out.
if the exhaust pipe is bigger than the exhaust port, leaving it that way wont matter, just remeber the size and shape of your pipe when you port the heads to match....