upper manifold to fuel body help!

[knuckle busta]

hi! i just upgraded to a MFI spider (borg warner) on my '98 chevy 4x4 k1500 excab 5.7 vortec and i can't seem to get the upper plastic manifold/plenum onto the fuel metering body all the way to the top like a factory installed unit.

i oiled the oval gasket with clean motor oil pulled up as hard as possible but there is still about an 1/8" or so gap from the top.(also torqed down the bolts hoping it would help pull manifold/plenum down over fuel body)i dont want a vacume leak after all that work & money.should i not worry about the gap?how is this done at a dealership?can you PLEASE help me?

THANK YOU, "knuckle busta" p.s. i used the original bracket b/c the new injector upgrade did'nt come with one.if the bracket was a little taller it seems that the upper manifold would go down all the way.