I have a 72 f100 4x4 360 with dual glass packs.3.5 gears. Carb is a mc 2100 1.08 with 49 jets. I live at 3000ft. The carb was replaced fairly recent. The old girl doesn't really seem to have the giddy up. I was thinking that maybe this carb was a little small. My old small block amc 360 had 1.21 venturis and 3.31 gears. It seemed to have way more power. I used to use the mc 2100 with the 1.08 and size 47jets .on my amc straight six. It gave that straight six some pep. Any thoughts? thanks, Joe

 

I'd pull the plugs and read them first, then do maybe more jetting and fine tuning adjusting the carb air/fuel jets. Also check dist.vacuum adavance is working. Check pointa gap. Maybe play with timing a little using a timing light not free hand by ear. Also use a vacuum gauge. Do a road test after each little retuning. Write down what your doing as to what works best. Then the naxt time you need to retune the old truck up you'll know what to do too make it run right again..my 2cents
orich

 

Yeah, the 1.08 is way small, although I actually had one as factory equipment on an AMC 360 that was a gutless turd. I had a 1.21 on my last built 300-6 and it was actually a bit small until it got polished out