looking to rebuild my 340

gniknayrb18 said
its just weird my 340 has a street demon intake on it with a street demon carb and i floor it and it just doesnt take off like it should.....my 5.9 cummins is much quicker and that doesnt seam right to me it has a cam in it just not sure what all they did to it before i got it...put it this way i use to own a 77 formula 400 with a sb 400 and muncie 4 speed it had 6x heads a torker 2 intake and a 750 eddy carb and that thing would scream and light them up whenever i wanted

could be several things slowing it down... one or two of the following would hurt ya:
low stall converter
low compression (what year is the 340 block?)
kickdown not adjusted right for the trans
carb not set up for the combo
vacuum leak somewhere so carb not performing like it should
ign timing out of adjustment

if you look at the spark plugs and tell us how they look it might give us some ideas.