need help asap engine problems

[special70gmc]

okay, i made a deal with my autobldy teacher that wile my truck was in his shop (im painting it now) he could drive it in and out of the shop to make room, BUT the f***ing truck never wants to start. it fouls the plugs every two days at least(acdelco r45's) hes getting really aggitated about this whole thing. all i know is the choke IS working correctly,the primary float setting is about an 1/8 inck down from the sight plug and the seccondary float over flows a little out the sight plug. mortec says i have a holley 4160 the # is 80508 and its jetts are (F)72 (R)plate 134-21 6.5
im nt sure how big the accelerater pump is either.

is this carb too bug for my combo? do i need a 650? please help thanks alot -kyle



355cid LT-1
10.3-1 compression
total seal rings
comp xe274-h cam w/comp roller rockers
vette ''492'' castings w/bowl port
2.08/160 manly ss valves
forged + balenced rotating assembly
1 5/8 headers 2 1/2 exaust w/flows +h-pipe
rpm airgap intake
holley 750
regular gm hei
tci street fighter trans w/2400stall
4:10 posi rear