Id recommend either a 2mm or 3mm HG. and you do not need to build the block to reach 450+ rwhp. I DD @ 18psi and have had my car boosted up to 24psi without any problems.

 

I'd say stick with the stock gears for now, and see how the car drives once it's boosted, then make a decision on that. I was considering 4.57's for years but now that I'm running more boost I'm actually kind of glad I didnt get them as the car rips through the gears pretty quickly as is. I may change my mind later on down the road, but for now I'm not really considering them at the moment.

 

The 4.57's are supposed to be much stronger than the stock 4.10s, 4.44's, and 4.77s which I believe are al made by Mazda.

 

true, guess if the car is going to be seeing time at the dragstrip then go with the stronger gears.

 

Its not the gears you really have to worry about. IMHO its the syncros in the tranny that are weak. One misshift @ high hp and the syncros's go bye bye....Trust me, im speaking from experience. Crossing fingers the 05' tranny holds up better then the 03' s did

ps...dont forget to add a good clutch to your list

 

Cryo the stock gears and housing. I have 4.57s and they are too much with over 400 hp. Too much wheel spin.

Cryo the whole engine and you will not have any problems with 40 psi.

You will need a minimun of 1000 cc injectors. 750s will be too small.

 

I don't think you need 1000cc injectors to reach 500 rwhp. From my discussions with InlinePro's John Lee, I'd stay away from RC750 injectors if the fuel pressure is going to be over 80 psi. Supposedly, they are reworked 440cc?? injectors. Modified internals for more flow, but they choke at about 80 psi.

Cryo treatment is not the answer to all problems. Get Inline's built block. Bombproof

 

Alright, so go with 1000cc injectors, stock cryo treated gears, and a 3mm head gasket. Can anybody recommend a good brand of 1000cc injectors? My friends with Supras seem to like the 1000 and 1600cc Precision injectors.

 

Our 675 will support 450rwhp easy on certain turbo's / tune.

our 880's have supported 590rwhp.

our 1,000 cc's and 1,600 cc are for certain race applications. I think they are overkill, but they ALL are great injectors.