BEFORE THIS TURNS INTO A 305 VS 350 FLAME WAR.... I JUST WOULD LIKE TO KNOW HOW BIG COULD U GET A 305 BETWEEN BORE AND STROKE!! i belive stroked its a 329 or somethin like that... and i have a friend who bored out his monte's 305 to a 315 or 312... if i use my math correctly... will i get a 339 or a 336ci? am i off? could one elevate there engine to a 350?? i dont wana hear 350 cheaper to build yea i know...trust me... i know...

 

Weeelll, you could pull the block, and possibly bore it over a huge amount, and sleeve it. I doubt any sane person has ever done this to a 305, but if you're really that anti 350, its probably the route to go for extra cubes.
I don't know if there are any major differences between 305 and 350 water jackets, so if you wanted to go this route you could end up with a 4" bore. Doing this would be costly, and probably a dumb idea when looking for extra cubes.
If you don't do that, then stroking it with a 3 3/4" crank (400 sized), and boring 0.030" over, you will get a 334. Going 0.060" over will give you a 339, I believe.

I can't fathom why anybody would do either, considering the cost/problems related to both. I'm not going to say you should step up to a 350, but if you're going to keep your 305, look into ways to get more from what you have. Don't try to make it bigger, just try for more hp/cube. 400 unstreetable hp is not impossible on a stock bore 305, NA. I believe a guy named Preston Smith managed to run 9's with a power adder (maybe 2) on a 305 block.
As a matter of fact, I think I'm going to try a search on that one, see what I can come up with.

EDIT: After searching, all I can find is people talking about him. There doesn't seem to be too many facts about his setup.

 

About the only reason you would want to stroke a 305 is if you have a visible inspection that states an original engine must be in the car. Except for the special 400 balancer the 334 would look just like a 305 with all the proper casting numbers.

 

Found it on camaroz28.com:

Preston Smith's 1985 Iroc Super Chevy March, 1994

305 TPI: LB9 TPI motor. Mods: 1990 Roller block-.030 over, J&E hypereutectic pistons-tops ceramic coated, splayed four bolt mains conversion, forged crank, Mechart stainless steel connecting rods, Lingenfelter 272 roller cam, AFR stage one aluminum heads, stainless steel roller rocker arms, Arizona Speed and Marine runners, 52mm TB, 30lb/hr Bosch injectors, 16 psi Vortech supercharger with air to liquid intercooler, TH700R4 trans with 2500 rpm converter, Dana 44 rear with 3.54 gears, Hedman 1-5/8" headers, dual 2-1/2" exhaust with Sonic Turbo mufflers, DFI fuel injection. Car weighs 3835 lbs with driver.

Performance: On street tires with street gas, 11.7 seconds at 116 mph. On slicks with race gas, 10.86 at 125.3 mph, 60 foot time is 1.53 seconds. The motor makes a computed 583 hp, which is very impressive from only 308 cubic inches. Just imagine how fast it would be with a 420ci motor, with the same hp/ci it would make 795hp.

 

there is no ryme or reason to my maddness... i just wana know... how big could u get it to be? i dont wana do it.. im just askin how big could u get it to be....and heres another question.... since a 64cc chamber would be too big for a 305..... how much further would u need to bore the 305 to where 64 or 350 heads could fit.... its verry hard to find 58cc heads that are vortec...there probably out there.... just havent found them.... and what are the advantages of the S/R torquer or the Vette heads over stock? thanks fellas

 

I've heard that the vortec chambers are usaully a little smaller than 64, like 61-62. If your rebuilding your 305 I would just 0 deck your block and/or mill the heads to get to your desired compression ratio. If your hell bent on keeping the 305 I would go this route.

 

305 blocks will not bore out to 350 bore size. THe cylinder walls are not thick enough. Most will not go to .060" over.

The biggest you can safely make one with the stock stroke is .030" over which is just over 310 CID. If you want to risk it, you may be able to bore it .040", which will make it almost 312.

You can put a crank with the stroke of a 400 (3.75" as opposed to the stock 3.48") in one. With a .030" overbore, that makes a 334.

Like Stephen said, that costs more than getting a 350 block, and produces less inches and les power. IMHO it's a stupid thing to do but that doesn't prevent people from doing it.

The easiest, cheapest, most effective CID upgrade for a 305 is not a "stroker kit", but rather a "bore kit"... a 350 block. The dividing line between modding / repairing your existing 305 and getting a bigger motor is the point where you have to bore and buy pistons... compared to the cost of that, a core 350 block is almost free, and it makes no sense to spend all the money on a 305 when for a couple of more coins you can spend it on a 350 block instead, and add 45 cubes.

Any 350 heads will bolt to a 305 block. Whether they will work or not is a different matter; the valves may not be above the bore, but rather above the block deck, which will make them hit the block when they're opened. And even at less valve size and lift, a larger valve than what comes in 305 heads may be so close to the bore that no air can get around that side of it. That depends on the particular castings, as different casting locate the valves in slightly different places.

 

Yes.

 

I have that issue. Very good read.