I've heard that on the 98' and '99 models taking about 10 thou of the head will give slightly better performance without sacrificing reliability. Would it be safe to run pump gas after this mod? Some people say that the 00' and up are a bit tighter up top from the factory. Any advice on this would be appreciated. Would the performance gains be noticable?
Blue Devil
New member
Yes I have done this mod to mine. 
30 of the heads and 3 base gaskets.And yes there is a noticeable differance.
30 of the heads and 3 base gaskets.And yes there is a noticeable differance.
nailsandrails
VIP Member
It is cheaper to get a .030 base gasket from Maxximum Perf than it is to get 3 stock base gaskets. Just trying to save you a buck! Actually about 20. I just did this to mine. Supposed to add 3-5 HP. 
shortstop20
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So 30 thousandths off the heads, a .030 base gasket = 3-5 HP AND it will run on pump gas? Any jetting changes. Will it run on 88 octane? That's all I can get at my gas station 
Its sounds as though this setup changes your port timming and keeps roughly the same compression. If this is true it should be ok running on pump gas. Will there be any loss in bottom end power?
The powervalves will look after keeping your bottom end power. The main exhaust port will still remain closed until the powervalve opens.
yamaholic22
Active member
Yes it will still run on pump gas, but you should be running premium in your srxs anyway boys