Before I order

[Old Head]

Just have a couple questions before i order my motor mods.

1) I noticed that C&D racings je kit comes with gaskets and was wondering how they hold up?

2) Whats the reason for the crf 450 cam chain and is there a certain year that it has to come from?

3) Does anyone have a picture of good rocker arms as opposed to ones that are damaged. I don't want to install a new cam with bad rockers. My motor is in tip top shape though.

4) Has anyone installed gt thunder studs and what needs to be done to install them? Also are they really nessesary for a 416 11:1 compression? or will the stock ones be fine.

I think that about covers it.:macho

[pit/wood]

I dont know about #1.The stock 400ex cam chain stretches a alot.You can find a heavy-duty chain easy enough.I dont know about using a crf 450 chain.I believe the cam chain stretch becomes an issue after you install an after market cam.more aggressive lobe,higher lift lobe,and a faster drop of the follower all contribute to cam chain problems(race type cams in autos take care of this by using gears instead of a chain).I do know that the stock head bolts are soft and stretch when combined with high-comp. pistons.(more heat ).12mm hardened bolts are used to increase thier stability under heat,keeping even pressure on your head gasket.you have to tap the threads for these oversized studs(best to use a thread-forming tap and not a thread-cutting tap.I have seen hardened studs that do not require an oversize hole,but can not find the source for them again...Hope I helped and keep asking ,lots more experiance i n here than I have.

[400exrider707]

1)What brand of gaskets are they exactly? Im sure C&D will hook you up with some quality ones.

2)The stock cam chain stretches and can skip teeth thus throwing off timing and doing much damage. You need an 02 CRF cam chain. It is identical to a heavy duty aftermarket one and much much cheaper. C&D can get those too I believe.

3)Post a pic of yours and Im sure someone can tell you if they're bad or not. generally if the chrome platins is wearing off and you can feel grooves in the face with your fingernail you should probably get some new ones.

4)I dont think they are necessary at all with an 11:1. You should be fine. If you do get them, send your cylinder right to GT Thunder to install them because it needs to be PERFECT! They all have to be set to exact heights and perfectly straight. I've heard some stories of guys having local machine shops do it and they mess it up and the cylinder is scrap, then they have to go through a whole ordeal trying to get a new one and have the shop pay for it.....

Hope this helps.