Thread: Congratulations, its a... 305?

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I recently found an add in Craigs List that had a 350 small block for sale for $65. I called to ask about it and the man says it runs. Of course I buy it. I buy this motor with intentions to beef it up and bore it out to a 383 and then put it in my '87 K5 Blazer. Here's the problem. I tore it apart and then ran the numbers. Its a damn 305 with 350 heads, valves and crank. But then I realize that it doesn't matter because I plan to bore it out anyway. I did some research and I keep hearing this roomer that you cant bore a 305 to something that size because the cylinder heads will be to thin. How can this be. I know for a fact that you can bore a 350 out to a 402. If its the same block then you should be able to do the same with a 305. Is this true? Its on the same block, what does it matter?

350's cannot be bored to 402, that over 50 cubic inches not possible. to make a 383 you have to use the longer stroke cranshshaft from a 400sbc. the 305 is a good solid running sbc, just not the fastest ever built.

but you can stroke a 305 to a 335 by using the same 400sbc crankshaft.

Man if you got a rebuildable block and good heads for $65, what's to bitch about I'd bauy all the good 305's I could get at that price

You CAN bore a 350 to make a 402... I've done it!
All that you're saying makes sense, but why cant you bore out the 305 to a 350. I did some measurements and there is enough room to go bigger. Like I said before why not bore the 305 to a 350 and then add the crank from a 400. Makes sense to me, but i'm just a new guy looking for help. Thanks

what is the bore size now???? A 350 has a 4.000 bore and most modern blocks can only be pushed to about .060 over, even less on some, more on others

Do you know the block casting number????

The bore size is 3.73. I want to go to 4.000. The block cast # says it was cast for the 350 and the 305. If I can't bore PLEASE explain to me why.

the cylinder walls aren't thick enough to ---also $$$ to bore the block would be more than just buying a core 350 or 400 block
gasser 196 has a 400 for sale

If the cylinder walls are too thin how did GM use the same cast for the 350?

305 and 350 block castings aren't the same...they do share the same 3.48" stroke and the external dimensions are the same.

What is the casting number????

Even if it could be bored to 4.000-----I could do one that was already at 4.0 cheaper than I would bore yours .250-----

Good news. We found a 350 in good shape for $150. Headed down to Auburn to get it tonight. Problem solved.

even at .125 i only gain 19 cubic inches 283 to a 302, how do you gain 50?? that must be one heckuva bore job.

FYI, a 305 crank is NOT the same as a 350 crank althought they both share the same stroke and bearings......a 305 crank is a different part number with different counterweights when compared to a 350.

I've got no more argument for you guys. You guys were right. And by the way robot, I got no clue what you're talking about. I know they're not the same. Thanks though... Thanks guys.

P.s. The new 350 I just picked up is in awesome shape. Seems like New Yorkers dont know what they have before they sell it. I'm making enough profit to pay for gas and more motors to scrap. Maybe i'll turn it into an e-bay business.

I didn't think discussing facts was arguing----we asked for a couple things you didn;t provide so we passed on info which you disregarded