300 v. 240

Please excuse the rudimentary question, but I'd like to know if I can switch my stock 240 engine for a 300 in my 1966 Ford Van without making significant changes to the stock engine compartment.

Thanks
Jason

Straight swap if it is a carbureted 300. The motors are basically identical on the outside.

It's a little tougher for a fuel injected motor, since the intake system won't fit in the doghouse. Neither will the EFI exhaust manifolds. The EFI engines also don't have a place for a mechanical fuel pump, so you would have to mount an electric pump back by the gas tank. You can swap over everything from your 240, including the ignition system, but I understand there are some concerns converting an EFI engine to carburetor because the EFI heads were "fast burn." Never done it, so not sure what's involved.

Yes, like jdlaugh said, straight swap. As I know the only difference is the stroke of 4'' instead of 3'' because of the different crankshaft.
I got a 70s 300 in mine with the stock 3 on the tree manual tranny, 10'' clutch, stock 164teeth flywheel, clifford intake, holley 2bbl carb and headers.
I bought my van as a 240 but when I had to take off the headers and intake to change the leaf spring bushings!! I saw the D7... cast number on the engine block. So this was not the original engine. After some research in the web I found out how to indentify a 300. I measured the stroke through the spark plug hole and voila... 60cui plus in 5 minutes.
Tell me if you need any measures, numbers or pics.

IMO,,,,  its TWICE the motor!!!!!  The torque is much better and allows a greater range of gearing. I replaced a fast 240 with 3;50 gears,, but always looking for another gear at 80 because of the gearing.
  Dropped to 3:25's and it would start to die going up a long hill and down to 2nd gear.  Blew it up and installed a 300. Cruised all day long a 80 no problem and drove up the SAME HILL at 80 instead of dropping down to 2nd.  The torque is fantastic and had considered dropping down to 3:00 because of it.
The 300 uses a dampener bolt and the fan will hit it but an easy fix using a 1/2" spacer between the fan and the water pump hub.  Also dual belt so you can easily upgrade to a 3G alternator...
  Just be aware that all the big sixes were heat generators and gas percolation issues with the exhaust bolted to the intake manifold. Stock exhaust DO NOT PUT ANYTHING PLASTIC next to the passengers side rear part of the doghouse,,LOL
VicSoCal

Does anyone know any good engine builders in Southern California? I'm not looking to get crazy but would like to improve performance. Found the links below and I'd say they are roughly in line with what I'd like to see in the new motor. At the end of the day I want the new engine to fit into the stock doghouse without any modifications. Also don't want it to be super loud either.


http://www.powernationtv.com/episode/EP2014-04/hopping-up-an-old-skool-six-part-2

http://www.powernationtv.com/episode/HP2013-18/a-buildup-of-fords-classic-inline-six