I believe the 6bt is around 40 inches if I remember correctly from the last time I was playing with a tape. I cant say exactly but I'd imagine thats probably around 10 inches or so longer than a big chevy. I'll also go without the mechanical fan, and depending on what radiator I can find from a scrap yard will dictate where it goes. I'm thinking a radiator from a tractor would be ideal. Tractors move slow while at heavy load and still keep them cool within a relatively small radiator.