Amoreuxi

Do consider the permaseal MLS gasket. As good as the cometics. They also do inlet etc gaskets for the rb's.. The inlets look a little better than the factory stuff but factory is better on the exhaust side. The few times I've replaced my inlet gasket (just removing head playing with restrictors etc) i've found the factory inlet gasket appears the be leaking 'slightly', the permseal doesn't appear to have, its a little chunkier on the metal embossed seal. I've never machined the inlet/head face so it may simply be that but the permaseal inlet gasket definitely sorted the very very slight seep i had. The Permaseal MLS i grabbed from motor traders for a little over 200. the inlet/exh gaskets etc was dirt cheap. $100ish all up from memory.

Machine the lug down as the others have said. Works perfectly fine.

With the price of rods these days its worth throwing a set in. If you decide you want to throw set of cams, plenum and 'decent' balancer at it then you feel safe to flick her to 8000rpm odd. BUT. with 8000rpm you'll be pushing 340rwkw+ and most likely a gt35r unless your ringing the neck out of a GT30, not that ringing the neck out of a GT30 is a bad thing. Its a damn near perfect setup for the power IMO. The response and power delivery simply cannot be described other than a big power N/A with a big top end. I miss mine. Just don't forget the requirement for a decent clutch and with 340rwkw comes the likely possibility of breaking an rb25 gearbox if the clutch and tyres are decent. Torque breaks things.......

A light spray of Hylomar regardless. Never had an issue doing so, once had an issue not doing so. And face the head its only $40-50, they give it a bath that will clean all the sludge and crap out of it.

For a streeter. Going much smaller than a GT30 and you need to look out for the old torque vs rpm vs gearing. The RB30's choke very quickly with a small turbo and begin hurting over 5500rpm of which seriously kills your acceleration once up and rolling. If the rpm doesn't match the gearing you'll find you will be shifting considerably earlier and the old rb25/20 setup was quicker and importantly more fun to drive. GT30 .8 - 2800-3000rpm all its boost GT35 .8 - 3500rpm ish all its boost GT35 1.06- 3800-3900rpm all its boost. Don't let that gt35 1.06 300rpmish fool you the 1.06 does feel a fair bit more dull to the .8 in first and second. The .8 makes more boost at a lower rpm where as the 1.06 tends to making very little then snap on hard. In my experience anyway.

Build a package - every part is to suit another for the power goal. RB30's are dime a dozzen. Go the 87mm, why not, every little bit helps. Your only after 450rwhp. 555cc's - up the pressure slightly they will be fine. Drop the rear down to a .86, there's no need for the 1.06 for 450rwhp especially considering your running 555cc's. It will only introduce more lag and you'll be depressed when something with less hp kicks your arse. 450rwhp - drop a .5 comp cover on it with the .86 rear, perfect match excellent mid range and some very nice response in first and second. Matching GT30 territory but with an additional 30-40rwkw. Ford did a lot of testing with the .5 front cover, its a very nice match for a GT35R streeter on 98 pump looking for 350rwkw. What about a clutch, 450rwhp+ will need a considerably better clutch than a good exedy single plate. Consider the package, don't over do one area only to under do another. Your running a plenum, be sure not to shove in a set of cams, it will rev want too hard and you will spiral in to the $ of ATI balancers and forged rods, if you don't you'll rev her too hard and whats that KNOCK KNOCK KNOCK, oh sh$#T, maybe thicker oil will fix it... no it won't. In short.. Aim for 450rwhp don't over do it and it will be a cheapish package. Over 400-450rwhp and it starts getting expensive quickly. ATI balancer, high rpm, bigger injectors, cams, porting, more lag but more rev's, double/tripple place clutch then you start stripping gears in the ol' rb25 gearbox, then there's the traction issue that WILL present its self of which again will make you depressed as some one with considerably less HP WILL kick your arse... see where I'm heading. EDIT: Shove some forward cradle rake in to it - it will make the world of difference to the way it hooks up.