Thread: sb 305 question

Tweet

I recently aquired a 305 sb, that was said to have been made into a 327. all I have seen in the engine is the heads, castings are off a 350 sb, and guide plates have been installed, any other way to tell with out disassembling the whole engine?

Well, first of all, you can't make a 327 from a 305. They're two different block castings.

327 = 4.000" bore with 3.25" stroke
305 = 3.736" bore with 3.48" stroke

Just about the largest you could make a 305 is a 315, using a 0.060" overbore.

There is a way to measure cubic inches without disassembling the motor. We do it all the time at the drag strip with a P & G cylinder volume tester. Check around at some of the circle track racetracks or dragstrips in your area and inquire if they can "pump" your motor.

A 305 fitted with a 400 crank has 329 CI. (3.736" bore x 3.75" stroke)

You can get pistons for this set up.

Does not rev like the 305 but has more overall power and much better torque.

350 heads are rarely used on 305s. When they are used care must be taken to insure that the intake valves, in particular, do not contact the lip of the cylinder. 305 valves are smaller and closer together. 283 heads are occasionally seen on performance 305s and after market heads are also available.

400 cranks are externally ballanced. Look for a weight on the edge of your flex plate or flywheel. The harmonic ballencer will also be cast with a visable weight but it is hard to see when the engine is assembled.

thanks, Bib, I thought about that when I formulated my answer, but then I thought, NAWWWW, nobody in their right mind would put a stroker crank in a 305 block

orignally I had a 454 in my 87 chevy pick up, and I switched to the 305. the guy that had the block had told mt that it was a 327, after much research I came to find it's true nature. needless to say I have had to do alot f reaaranging with pullies and set of of the engine. Sure does not seem to have the power of my big block, but a little better gas milage. what are the hp ratings for the 305? it has a eldelbrock preformer intake and 650 cfm eldlebrock carb. jet coated headders, and hei distributor.