Need help with tire size

[1buick]

I need to know what tire size you guys suggest? I am running a basic almost stock set up. I have a walbro w/hotwire, 42lb injectors, stage2 turbo, 3000 converter, poston 206 cam, adjustable fpr,duttweiler neck IC, stock downpipe with test pipe, and 26" MT drag radials. I went to my local 1/8 mile track and my mph was only 77mph, should I lock my converter or go to 28" tall tire? Please respond asap because I have a date with a mustang in about 3 weeks, so I need to be prepared!

 

[t-typex1]

I dont think its the tire size thats hurting you. Maybe the tune or something. I have a stock long block, and with less than you on a TE60 I trapped 89/90 mph in the 1/8th. 12/13 MPH is a lot to leave on the table, especially on similar setups.