301 misses need help!

[farmall460ih]

bought a 301 motor and put it in a 460. the motor already had the petronix electonic iginition on it and dennys 8 mm wires on it. The motor runs great until it hits about 2400 rpms then it sputters real bad. the governor weights have been ground to half their weight and a stiffer spring is installed. it has 301 .060 lp pistons in it with extensive head work. running a combine carb with a number 29 venturi and a 4 lb fuel pump. today i put a new msd coil on it thinking it was that but it didn"t help. running 3116 autolights gapped to .025. any ideas? thanks in advance

 

[TWL]

I have a 301, custom cam, petronix ignition.It acted the same way. I took out the main load screw and drilled out a couple sizes with a number drill. It runs fine now. Hope this helps.

 

[jd plowboy]

i got my plugs gapped to .035 and had to run a 7 lb fuel pump on mine to feed the combine carb.

 

[farmall460ih]

what size number drill did you use for drilling out the load jet? we are already drilled out to .065. thanks

 

[jd plowboy]

if you have drilled the jets out and running the 4 lb fuel pump and it still misses i think you are running out of fuel. i was told that the combine carb sucks gas though the needle and has a passage on the side that it sucks out of also. my problem was fixed with the 7 lb fuel pump. i hooked mine to sled and it wouldnt even pull off at 2000 rpms until i put the fuel pump on. now it is fine. i was told that was the biggest carb IH built

 

[TWL]

I have a cheap # set from harbor freight. I used a number 42 but I checked it with a dial caliper and it read .092. I did forget to mention,I do not use a fuel pump,it's all gravity with a bigger fuel line. Hope this helps.