recommendation
 

im trying to buy a peavey valveking 50watt. i have an ibanez rg370dx. i want to buy new pickups aswell. i listen to metallica guns n roses, i want a neck pickup which will give me the soloing sound like marty friedman as im the lead guitarist in a band. im thinking of seymour duncans sh8 in the bridge and dimarzio evolution in the neck

Don't go for the invader. It sounds completely lifeless.
Also the evo is an incredibly sensitive pickup and will show off every slight mistake you make.

Something like a crunch lab/liquifire or JB/jazz combos would do everything your looking for.

and i was just checking out the peavey valveking. i saw thats its open from the back? can you tell me why that is?

btw should i get a single coil along with the john pettrucci pickup set?

I'm by no means an expert on the matter, but an open back gives the amp different bass response than a closed back.

+1
An open back when set 4-5 feet from a wall will fill out sound better than a closed back cab. A closed back cab puts more sound directly in front of the speaker where a open back will go forwards and backwards (and bounce off the wall behind) ;)

btw will i be able to get the tapped harmonics like eddie van halen does with the crunchlab/liquifire?

That is more technique than pickups ;)

but i just cant the harmonic sound with my infinity pickups? i get the harmonic but its not that audible nor does it have the same attack

Those pickups are not good at all so better pickups might make it a littl better, but I can get harmonic squeals from an acustic, so it is 99% technique. Just keep practicing and you'll get better.

Remember VH pickups were never what I would consider really high output, but more of a beefed up PAT Hb tone.

more recently he's been using ibanezes with neck pickups (how much he uses them, i dunno), but i think in megadeth he mainly used the bridge pickup (assuming that's the type of tone you want).

btw what is f spaced. do i need an f spaced pickup for my ibanez rg370dx?

F spaced is fender spacing (tremilo/floyd rose) if you have a tremilo bridge you will need an F spaced

i have a floyd rose floating trem. do i need f spaced.?

YES you want F spaced ;)

btw can the peavey valveking 112 be used at gigs is it loud enuf?

For most band situations yes it will be absolutely fine. If you going to do metal, I would at least use a 2x12, but that is me. I sometimes use a 1x12 combo for practice I have to dime the vol and it just works, but we are very loud and my 1x12 is only 15-20 watts tube. ;)

I highly sugest getting a amp stand or something to raise it off the ground and get it closer to your ear level.