buying an old junky 1971 DT1E barn find from a dude near where I live. did a little search on the forum prior to posting (im sure someone has talked about it before), would the 1971 DT1E engine fit onto a 1972 DT2? 

might be a longshot!

 

You should be ok... DT2 had reed valve and DT1 was piston port so might be some minor things with airbox connection? Hopefully if there is you could just use DT1 parts. 68-73 is all "first generation" with changes and updates through the years... but basic design architecture is the same.

1973 marked the new architecture for the MX racing models.... those design changes made it to the Enduro in 1974... so 1974-76 stuff is a lot less likely to fit a pre-74 model... 1977 was a another milestone where the race bike monoshock design made it to the 250/400 Enduro.... (happened in 1978 for the 125/175... no 1977 125/175 Enduro model in the US)

if y'all are interested, I could post about my trials and tribulations. I won't have the "new" DT1E until the end of the month looks like. buddy also has a 175 for sale... might have to take it home too. wouldn't be fair of me to leave it behind 

Did i mis-read your post & do you want to fit a "complete" motor DT2 motor into DT1 frame & yes it will fit straight in. Thinking cylinder swap.
Edit, looks like i'm on the wrong post. Not concentrating.Sorry.

Easy to do, that means I post too much!