the 300 was only ever used in trucks and industrial applications and the T5 was never seen on it I don't think. It may have the same bolt pattern as a 5.0 BUT that is a guess.
Are you thinking of putting one of those in a mustang? You will want to try and adaprt it to serpentine accessories to clear the radiator, and you will need a rear sump oilpan and a revised intake or bigger hood for overhead clearance.
Not sure how the motor mounts would work since it is longer than a 5.0/2.3 block. Would definitely need V8 springs, it would be more nose heavy than a 5.0.
I also have been thinking of a 300 I6 or a 250 I had a 71 maverick with a 250 with a header and a 2 barrel and it would run,I think it would be neat to see a inline 6 mustang...
If you want to learn more about ford inline sixes, go to http://fordsix.com .
A 300 will out-torque a 302, due to the longer stroke, all things being equal. Some (including myself) have looked into putting a 300 into a fox-body, and it won't happen without some fabrication. Will it fit in the engine bay? Yes-barely. The problem is figuring out how to set up an oil pan and other associated things down below.
A 250 is still going to be a little tall, but it has been done once I know of. A 200 would be the easiest, since '79-'82 Mustangs/Capris came with them stock, but you'll need the 200-specific K-member. A 250 has the same bellhousing pattern as a SBF, so that part is easy. A 200 doesn't, but you can still use a C4 or T-5. A late "big bell" 200 has 2/3's of a SBF pattern, and a SBF bell can be adapted.
on corral this guy was asking about how to put a V8 in an inline car, and had a pic of the inline6 crossmember... it has the mounts much farther forward, and looks like a 300 will bolt up to it rather easily if you fabricate a new engine-to-mount bracket.
I kinda want to do a turbo 300ci I6 one day. They are tough engines, 7 main bearings and stuff. 7,000RPM isn't out of the question, the trick is getting it to breath up there. Check out Clifford Performance for overpriced I6 parts.
There was a dude selling aluminum 250ci (if I remember right) heads on ebay, they're from Australia, but are actually OEM Ford parts. Yeah, the aussies get a lot of cool stuff we never even hear about. There's a quote from some Ford US exec saying how they just blew a huge pile of cash developing the V6, and the old Ford Aus. inline 6 would beat the snot out of it.