vibration in my 302 ?

I have a 84 302 with a 50oz balancer,motor came from a van,we put it in a 86 mustang with a t5 behind it now it vibrate at 3000 rpm , we also removed the studs that center up the pressure plate on the flywheel could this be the problem ? any help will be greatly apperciated.

Yes, those locating pins in the flywheel are needed to positively locate the pressure plate. There could be many reasons why an engine vibrates, but that is a good place to start since you know they are missing.

You said that the 302 has a 50 oz damper but what about the flywheel, did you mix-match them.

the flywheel came from a 86 mustang 302 with a 50oz balancer pretty sure it is the right one,there was no vibration in the old motor

Y did you remove those pins? And then not reinstall them??????

they were to big to fit the holes in the pressure plate that we had at first so we removed them, but in the end we just bought a new clutch kit,

Yup, you need those pins otherwise it won't be exactly centered and will vibrate. I had a vibration develop on my 289, it was worst at right about 3000rpm, and when I started checking stuff out, it turned out some of my pressure plate bolts had loosened up about 1/2 turn, and it actually caused the tip of one of those dowels to break off. I lucked out and just tighening up the bolts along with the 2 remaining pins the vibration went away, but in your case you need to have SOMETHING to locate it in the exact right spot.

BTW, you can get dowel pins that are machined down on half of the pin, for the situation like you had where the holes were too small. It's a Ford part, I can get you the part# when I get home if yo need it.

I have a similar problem with my 84 H.O. Didn't notice any vibration (only got to yard drive it first) before pulling the motor to put in the 63 Falcon.
I bought a new RAM clutch kit. I pulled the alignment pins to get the flywheel resurfaced, but couldn't remember where I put them.
Anyway, when the clutch (10") I ordered came, there where no alignment holes for the pins and the bolts had shoulders that were tight fitting through the mounting holes.
Part of the vibration I had was the exhaust up against the trans mount. I fixed that but it still seems to have more vibration than I think it should.
I also used new Bronco motor mounts to get the extra hight for header clearance. Could these mounts be too hard causing extra engine vibration?
Or does the weight of the three pins have anything to do with the balance as well as alignment?

This may sound painfully obvious but I have seen the same thing before when the pilot bushing / bearing was not reinstalled.

My 91 LX 5.0 had a vibration around 3000 RPM that turned out to be caused by a reman water pump. The plate that is pressed onto the water pump shaft that the fan clutch bolts to was not seated flush on the shaft so the fan had a wobble to it. Tweaked the plate so it was flush and the vibration went away.