EviLZ28

327 and a 350 are the same blocks. Just different stroke crank and piston pin placement. The blocks use the same bore and crank journal size unless you are using a pre 68 327 block. As for the 305, only thing I would personally use a 305 for is a paper weight. Not worth even rebuilding them as you will never get the performance you want out of it. Take the money and invest it in a 350. They are plentiful and can be found very cheap.

85_305

That's what I have always though (regarding the 327/350 being the same) until my one "know it all" friend said they are different What crank does the 327 use.. the 286?

DevilsAddvocate

How many cubes do you possibly gain? Boreing out in terms of adding cubic inchs just isnt worth the cost and longivety of the block imo. Especially on a 305. Boring to add cubes isnt worth it until you really start hitting above 400cubic inchs and even then i think its not worth it just because of the thinning of the cylinder walls.

EviLZ28

casting number for a large journal 327 is 3930809 cast and 3914681 for forged. You can also use a 307 chevy crank as it is the same stroke as a 327 and has the large journals #3941172

85_305

Why would it not matter if you bore your engine out to above 400cid? I also agree with you on the thinner cylinder wall thing. That is one reason why I didn't bore my 305 out is because I can imagine it wouldn't take much for the cyl. walls to blow out.

EvilZ28- What crank are those casting numbers for? And wasn't the 307 crank basically a 305 crank, as I have been told they are basically the same engine?

EviLZ28

EvilZ28- What crank are those casting numbers for? And wasn't the 307 crank basically a 305 crank, as I have been told they are basically the same engine?[/QUOTE]
The 307 and the 305 are totally different. The bore size of the 305 is 3.740 as the bore size of a 307 is 3.875 The 305 uses a 3.48 stroke just like the 350 and the 307 uses a 3.25 stroke just like the 327. I wouldn't build either one (305 or 307) as the bore's are to small. But they both are different internally. The numbers I supplied are the crank casting numbers for a 2.45 main diameter, 2.10 rod diameter and a 3.25 stroke.

On another note, you can also build a chevy 302 out of a 350 block. They also utilize a 4.00 bore and a 2.45 diameter main. The crank is the 2.45 diameter main with a 3.00 inch stroke. The only problem is finding a 302 crank. They are very rare. But where extremely high reving motors.

The 350 has alot of potential. It is a very common block and can be found for pretty much free if you search around. They have a wide variety of different configurations you can build utilizing this block.

DevilsAddvocate

No im saying if you have a 400 block with a virgin bore of 4.125". If ya bore it out .030 that brings you to 4.155". Now that would put your total displacement out to 406cis instead of 400. Not too big a difference. Now bore it out another .030, or .060 initially, and you have a grand total of 412cis. Still not too big a difference but the cubes are starting to add up. I dont think they add up enough performance wise to just bore out a perfectly fine virgin bore when you still have tons of life left on the block.

Now lets take a 305, 3.74" bore. Do it 30 over and ya get 3.77" equaling 310cis. Another .30 for a total of .060 over. Gets you a total of 315cis. Not really a big difference with how much added displacement you get from a 400 block (2cis less) and not a big difference in displacement from stock bore size (10cis). So hey if ya have the cash and 10cis or 12cis is worth cutting the expected life span of your block into 1/3rd of what it normally would be, then go 4 it. Just not worth it in my book. And thats what im trying to get at.

85_305

There is a such thing as a 302-crank? It's not a crank from another engine?

DevilsAdvocate- Now I see what your saying
Now.. lets say we are talking about a 6.5 horse lawn-mower engine. Wouldn't the effects of boring it out be far greater, as it is a smaller engine and everything works on a smaller scale?

EviLZ28

[QUOTE=85_305]There is a such thing as a 302-crank? It's not a crank from another engine?
Yes, It was offered in the 1967 through 1969 Camaro Z28
67-68 are small journal and 69 was a large journal.

85_305

Thank you for the information

92'RS-DFI

hEY IF THE GUY WANTS TO PUT TONS OF MONEY INTO A ENGINE THATS NOT REALLY GOING TO PUT OUT THAT MUCH POWER LET HIM. iT'S YOUR WORLD! As far as stroker kits for a 305 you have to see if you have new style or old one. The new style block stroker kits are really costly. Lunati makes at kit for like 1500 buck or so. For the kinda ching you can get a nice forged 383 or 396 kit. As far as 327's in SEPA you can go to like 6 junkyards and get them by the truck full. I think they only cost like 100-200 dollars. Good luck in what ever you do.

92'RS-DFI

What heads are you gonna use for any of these 305 combos. Stock? World S/R 305's?