'68 mod's

['68 longbed]

hello!

I've aquired a nice little '68 c10 longbed stepside that's straight and solid. my usual vehicle is tri-five chevy cars so I'm a little out of my element so far. so my questions to the wise ones are....

is there a newer style truck/car that i could swap a-arms , spindles,etc. with disc brakes...without major surgery?

this thing is geared like a tractor, will a four speed replace the three speed without having to chop crossmembers 'n stuff up? i'm sure a five speed will be an involved swap so I'm avoiding that in the short term!

thanks for any help! ya'll have a good fourth!