im looking at buying a 74 maverice with a 24o in it taht needs a rebuild i was wondering if i would be further ahead to get a 300 and put in with efi manifolds a offenhauser intake and a small holley would this make a considerable hp difference i have a solid 300.

 

Definitely doable. I'd go with the 300 over the 240. You don't really have anything to lose as far as power. Just keep that 240 head though, you'll need it for your built 300.

 

Are you sure it's a 240? The 250 was the standard engine in the Maverick. That's a completely different engine. The 300 uses the same block as the 240 so it will fit anywhere a 240 did. A 300 can be fitted into a Mav in place of the 250, but it's by no means a drop-in

 

Actually Mavericks came out in 69 with the 200 and that was the base engine for the whole run until they stopped in 1977. The only other engine that was available was the 302.

A 250 would be doable. However the 300 would be too tall UNLESS you went with a SCOOP HOOD.

Larry

 

hmm thatnks for the info i was just tol dit was a 240 by the owner i never researched it.

 

as far as i know the 240 was used only in trucks, but im not too sure

 

To straighten some things out..
The 250 WAS available in Mavericks as an option starting in '71. We had a '72 bought 2 years old. Also the 170 was the base engine and the 200 was optional. BTW, I took my first drivers test at 16 in that car and that car is also in the Blues Brothers movie...for 1/3 of a second
Yes, the 'small block' six, 140/170/200/250 is different from the 240/300 (considered the 'bigblock' inline six). The 250 is a little taller then the 140/170/200, but basically the same.

The 240/300s are identicle on the outside, same blocks and head, just a longer stroke crank, shorter rods and pistion compression height. Think 289 to 302 differences.
First introduced in 1965 on fullsize cars and trucks in both displacements. The cars only got the 240 while the trucks got the 300. Dont know for sure when they offered the 240 in a truck???
but 1972 was the last use of the 240 in the cars (full size), production lasted until '74 *I think*.
Also as you may know, since this is a truck forum, the 300 was in trucks up untill several years ago.

If your not real familiar with the engines the easiest way to spot the difference is the fuel pump and distributor. The bigblock six had the fuel pump close to the front of the engine and distributor about mid point. The small six is reversed.

Go with the 300, with an almost 4" stroke (3.98 to be exact...hmm same as the 428) it's a torque monster. Built right you will shock many small v-8 owners.

 

The intake manifold on the small block sixes was part of the head casting. Therefore, intake manifold was not removable on those engines. The 240/300 intake manifold is removable from the head.