[TR] TR4 engine in a TR3

[terryrs at comcast.net]

Hi everyone.  Been awhile since I've been on the list.  
Can someone remind me of the difference in size of the 4 engine in a 3 engine bay?  I seem to remember the 4's head causes the carbs to take more space?
Looking to rebuild a spare engine for my 3.

Thanks!
Terry Smith  (TS 58667)
New Hampshire