Hey there was wondering if i could get a few opinions or suggestions on what size of main jets i should use with my 421 at sea level, to give me a better idea of where to start and save the troubleshooting. I have Keihn D- Slide Carbs, i think my main jet size right now with the stock .040 bore is 130's, i thought when re-jetting bore size didnt come into play, but i was told when im going with the big bore (404 Vitos) it did, any info would be appeciated. If You need to know what other mods i have done, just give a post thanks - Kevin