Okay I checked the serial pad in the 55 and the Jimmy is a 248. I know everybody wants the big ones, but is anyone using the small bores?
A 248 looks just like a 270 or 302 but isn't nearly as desireable unless you are restoring a truck that came with one. If you are looking to sell it I'm sure someone will be interested, but it won't get the premium price you might with the bigger motors.
It would cost the same to hop up as a 302 with out the inches. If you want to use it in your project with simple look good bolt ons, it's still a much better engine than a 235 Chevy or even a 261 with a .060 bore. Lots of guys think it's OK to run a 235.
the block can be bored to 3.9375 and the 270 crank is a drop-in. makes a 292 incher. that's what i'm doing with mine, and the 270 crank was very inexpensive. the 248 crank will get saved for a 302 block when one comes my way for the right price.
What size will your 248/302 come in at then?? I'm looking for a spare for the Hot Rod.But like everyone else, i'm looking for a 302. I have a spare 270, but the head has a cracked exh port.
With some good popup pistons, a big port head, cam, induction & ignition you won't have to make any excuses to anyone.
270 and 302 are both 4 inch stroke engines. Why not use the 302 crank in the 248 and the 248 in the 302? How did the 270 get in there?
Well then if you put the 270 crank in the 270 and bore it to 3 15/16 it will be a 292 inch motor. What's up with putting the crank in the 248? Or you just have a 4 inch crank and no 270 - 302 block? Maybe it would make sense to get one. 270s are cheap. Make sure you get the rear main bearing in the right way. Lots of GMCs went down in flames because of that.
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