Ok this might have been talked about before but I could find the right forum for this. So I have a 98 5 speed gsx with top end work and stock bottom end. It's not the revised 7bolt motor. The built date is march 1998. it has 132k miles on body/bottom end and about 150 miles on top end. A week after owning it and driving it with no problems my car started acting and the crank went and who knows what else. What shitty luck because the guy I bought it from said that his mechanic said there was no need to rebuild the bottom end but who knows if that was a lie the shop told him or he told me. This is what is done to the top end
Brian crower 272 cams
BC valve springs
Supertech valves
Top line lifters
New oem head gasket
Arp head studs
Adjustable cam gears
Arp cam bolts
New ngk plugs and wires
New slave cylinder
New front axles
STM intake adapter and filter
STM EGR delete
STM balance shaft eliminator kit
B&M short shifter
Car has a SRS full exhaust with no cat.

So next week I have an appointment to take my car to R&D Automotive in Carol Stream IL to have it rebuilt/mild buit. I was told since my head has work done to it that I should do a mild build and not an oem rebuild. My goal for the car right now is to have it push 400-500 but to be able to keep the stock trans that has a new aftermarket clutch don't remember what brand but its not oem. I know after 400hp problems start to happen but I want to be able to save money and get a shep trans but that's next year. Also in the future push 600hp and maybe track it here and there. I want it to be a fast dd but a clean show car. I like the stock look and would not take seats out for less weight. Would add carbon fiber to the car. My car is lowered and im happy with that and has aftermarket 17" rims and it looks sexy. I my question is what would happen it I oem rebuilt it with built head? I know it was before I had problems but could that be why it happened since it wasn't built with the head? So what would the reason of a mild build be? Like if I go a evo route. LIke I was told with an mild upgraded build it would be safer and I wont get crankwalf? So basically what is the difference of a oem rebuild and a mild rebuld on a built head? My next question is if I go mild build to get 400hp out of it what internals would I need? Like what you think I should have don? what you think a shop would charge for all that not with supporting mods? I know ill need supporting mods also but what do think ill need? I know ill need a bigger turbo, fmic, wally 255, bigger injectors, upgraded bov,safc, upgraded manifold, boost controller and gauges. Might be forgetting some stuff. Prices would be a great help also. I am thinking used for the supporting mods and id buy from people i know or recommendations. Now if I do a mild build and don't and supporting mods what could happen to my build? I know ill need a tune. I just bought the car a month ago so I had enough money to pay for it and I have money for the mild build but not as much for the supporting mods. Now that I have the chance im thinking of mild building it. I know I shouldn't build the car till I have money for the supporting mods but im thinking of waiting till I have all the supporting mods. I also have a 91 tsi that needs rebuilding with 86k miles and 1000miles on the rebuilt 5 speed trans and have the chance to trade my tsi for these parts
eromotive regulator
780 pte injectors
wally 255
Evo 8 maf
punishment short route fmic that was on a 1g but id need to cut the piping to fit my 2gb.want to keep the fog lights
precision 58 58 ball bearing no shaft play
evo 3 ported mani
I just don't know what there all worth and if its a great deal to trade for all those parts. Btw my car is very clean. I know ill need a fuel rail also which the guy doesn't have. So since these are very good supporting mods/brands im thinking of doing the trade but again not sure if its a good trade. Help on that would be great.
With my gsx im doing it right and not going cheap but again im not going to spend 10k in it

I know this is a lot to be answered but im new to dsm's in the last year and a half and im learning still and could use as much help as I can. Thanks for the help in advanced. There might be questions I forgot to ask but if I have any questions later ill ask. If you could leave your Facebook username or email address so I can get in touch with you after you help out if I want to ask you for more info on your answer or I think you be a good help to me. I know its my car and build it the way I want to but it's always nice to get help