Brad-ManQ45

Then you should be golden...

You may not GET to 6k with any power...

Top end will be choked off a bit. Your power will be in the low to midrange rpms.

It'll be choked off a bit and start to spool around 2800 with full spool around 3200(estimated). Stage III turbine is like a 68 mm inducer and 62.35 mm exducer. The compressor wheel you are describing is awfully close to the 50 trim T04E and is a good match for the engine if not turning over 6k.

I don't think you have your trim specs right. Trims are usually whole numbers. The 74.2 just so happens to be the measure of one particular turbo e wheel's inducer diameter - and it is for a GT3076 turbo. A 50 trim compressor section is one of the just right compressors for our size engines in the normal journal T3/T4 series turbos. If you want lower spool the the T350 turbine (stage III) would be perfect. If you want more top end power then go with a stage V turbine.

That looks like a stage 3 turbine which is good for street. You need a .63 A/R turbine housing - your spool will be somewhere around 3100 rpm.

If you were running stock boost before this turbo change then you have turbo injectors because you'd have leaned out with NA injectors. When was the last time your injectors were cleaned? Have you checked each for proper function?

Ok, so stock turbo injectors. If you haven't raised the boost to much more than 10 psi you're ok with the stock injectors. The wideband sensor and controller need to be tested.

You failed to specify what engine the stock injectors are for. If for an NA engine then yes, you need bigger injectors. If for a turbo engine then that isn't your problem. Have you gotten an msq from someone with a basic turbo setup and tried it?

Can't put liners in and have them supported at the base...

If it will work with solid lifters then it looks to be pretty close to the "C" cam and would work well... Not so sure it would work with the hydro lifters - that lift figure is a big bump and not much more duration to tame it...

That would be .443 lift and 212° @ .050 lift, total duration of 260°...and whatever the radius of the base circle was reduced by is what you would add to the lash pads thickness. That is the way Schneider derives their figure for their hydraulic grind that MSA now sells. Did he keep the same opening rate/ramp angles as original? If so it's probably too steep for non-hydraulic lifters. The amount of lift might be too much for hydraulic lifters. If in fact he kept the same ramp angles as original then I'd say that cam is useless.

You're probably gonna be better off with getting one of the Isky cams that have been documented on this site because of the hydraulic profile. BTW - what are the specs on the regrind that Delta did and what lash pads did they say to use?

Actually a bit self serving on my part - I want to know if someone CAN Regrind a turbo P90a cam with a bit more duration and a bit higher lift that will work. I'm only looking for peak power at 5800 rpm and max rpm ~6k.

You can probably get away with a bit more duration but not much more lift. He will have to tell you what thickness of lash pads to use to make up for the smaller base circle.