3rd gear dying
I have a 1973 chevy c20 3/4 ton and have a fairly new 350 block I bought it at a used car dealership and it's a 3 speed so low 1st 2nd and 3rd it's ok but when I put it in 3rd and try to give it power and push the pedal to the floor for fast acceleration not all the time just everyone now and then but it begins to hault and almost die like it looses power all of a sudden but if I do it slowly it speeds up normal what do I need to look at?