Can you make a 305 stroker with 350 crank and rods?

[AyWoSch Motors]

As the title says, can you make a 305 stroker with a 350 crank and rods?
What would it be? Would it be a 327, or a 340, or is it even possible?
I havent done any research, just dreaming here.
I have a 305 that wrecked the crank and rods, and I have a 350 that is dead, but the bottom end is okay.
Could I potentially put the parts out of the 350 and put them in the 305, and make it work?
Thoughts....

 

[wanderinthru]

Going on memory of things I've read, so a great possibility I'm dead wrong. A 350 crank in a 305 bored block would be a 305. Bore size is the differance. 327 has the same bore as a 350, but shorter stroke. All the blocks are pretty much the same, small blocks, cranks, stroke and bore diameter is what sets CI's.

 

[Turbo4whl]

Thinking about this also, I checked Wikipedia for some info. Yes the stroke is the same, but depending on the year of the 350, journal size may be different. The other thing I was thinking, the crank counterbalance weights would be matched to the larger pistons of the 350. If that is the case, it will fit, but sure won't run smooth.

Maybe the crank is balanced to it's self, and the different piston weight does not matter.

Wikipedia Chevy Small Block

 

[Bennyt]

Rods are the exact same. 305/350 cranks are same stroke but 305 has holes drilled to lighten it to match lighter pistons for balancing. You can have a 350 crank lightened for 305 use but not practical to put a 305 into 350 as it would cost a lot to add weight. I've never seen it done but I guess you could use a 400 crank in a 305 to build a stroker but would possibly go into the water passage when clearancing the block at the base of cylinder.

 

[Bennyt]

Crank journal size, as far as I know are the same on all 305/350SB. There is a smaller journal on early 262, 265, 283, 327 and a larger on 400 sb.

 

[AyWoSch Motors]

Hmm, interesting. I had thought a 350 stroke was longer for some reason. Good to know.
Seems like if the journals are the same, and the rods are the same, it wont change anything. The counter weights are the only thing. Theres not a huge difference in size between the 2 engines' bores. Should run, if anything the off balance may wear parts faster.

Well I'm gonna give it a try and see if it fits. I'll let you know how it turns out.
I have 2 junk engines sitting there, might as well take 2 and try to make one. Might be fun, could be bad, ya dont know till you try.

 

[Grumpy]

I am with Benny on this.
I will add if you are planning on spending money, start with a 350 and not a 305. The 350 will normally handle an overbore of up to .060 and still be sound, while a 305 punched out will still not equal a 350.

 

[wanderinthru]

Hmm, interesting. I had thought a 350 stroke was longer for some reason. Good to know.
Seems like if the journals are the same, and the rods are the same, it wont change anything. The counter weights are the only thing. Theres not a huge difference in size between the 2 engines' bores. Should run, if anything the off balance may wear parts faster.

Well I'm gonna give it a try and see if it fits. I'll let you know how it turns out.
I have 2 junk engines sitting there, might as well take 2 and try to make one. Might be fun, could be bad, ya dont know till you try.

Be sure you use the rod and journal bearing from the block your taking the crank from.

 

[wanderinthru]

Thinking about this also, I checked Wikipedia for some info. Yes the stroke is the same, but depending on the year of the 350, journal size may be different. The other thing I was thinking, the crank counterbalance weights would be matched to the larger pistons of the 350. If that is the case, it will fit, but sure won't run smooth.

Maybe the crank is balanced to it's self, and the different piston weight does not matter.

Wikipedia Chevy Small Block

When you say journal size, is that ID or OD?

 

[Turbo4whl]

When you say journal size, is that ID or OD?

In 1966, General Motors designed a special 302 cu in (4.9 L) engine for the production Z/28 Camaro in order for it to meet the Sports Car Club of America (SCCA) Trans-Am Series road racing rules limiting engine displacement to 305 cu in (5.0 L) from 1967 to 1969. It was the product of placing the 283 cu in (4.6 L) 3 in (76.2 mm) stroke crankshaft into a 4 in (101.6 mm) bore 327 cu in (5.4 L) cylinder-block. The 1967 302 used the same nodular cast-iron crankshaft as the 283, with a forged steel crank that was also produced. This block is one of three displacements, 302/327/350, that underwent a crankshaft bearing diameter transformation for 1968 when the rod-journal size was increased from the 2 in (50.8 mm) diameter small-journal to a 2.1 in (53.3 mm) large-journal and a main-journal size that was increased from 2.3 in (58.4 mm) to 2.45 in (62.2 mm). DZ 302.

-Wikipedia

This is part of the information I found on line. I added the link in my first post. I don't know if it is correct. But like @Bennyt stated, it would be an early block. The Wikipedia calls out the 350 as one of the blocks with a bearing/ journal size change.

........ The counter weights are the only thing. Theres not a huge difference in size between the 2 engines' bores. Should run, if anything the off balance may wear parts faster.

My thought again, at idle it will shake. When you rev it up it will come apart! You must rebalance the crank.

 

[wanderinthru]

@Turbo4whl, yea wasn't thinking when I asked, typed that. Do appreciate it though!

 

[Bennyt]

Definitely have to rebalance to go in 305. It would tear apart very quickly. And no way would it be drivable. Like driving on square wheels.

Nothing wrong with putting together a 305 if it's what you got but I wouldn't be putting any serious money into it.

 

[rt66paul]

In 1966, General Motors designed a special 302 cu in (4.9 L) engine for the production Z/28 Camaro in order for it to meet the Sports Car Club of America (SCCA) Trans-Am Series road racing rules limiting engine displacement to 305 cu in (5.0 L) from 1967 to 1969. It was the product of placing the 283 cu in (4.6 L) 3 in (76.2 mm) stroke crankshaft into a 4 in (101.6 mm) bore 327 cu in (5.4 L) cylinder-block. The 1967 302 used the same nodular cast-iron crankshaft as the 283, with a forged steel crank that was also produced. This block is one of three displacements, 302/327/350, that underwent a crankshaft bearing diameter transformation for 1968 when the rod-journal size was increased from the 2 in (50.8 mm) diameter small-journal to a 2.1 in (53.3 mm) large-journal and a main-journal size that was increased from 2.3 in (58.4 mm) to 2.45 in (62.2 mm). DZ 302.

-Wikipedia

This is part of the information I found on line. I added the link in my first post. I don't know if it is correct. But like @Bennyt stated, it would be an early block. The Wikipedia calls out the 350 as one of the blocks with a bearing/ journal size change.



My thought again, at idle it will shake. When you rev it up it will come apart! You must rebalance the crank.

I remember using a steel 283 crank and putting in in a 327(back in the day) We called it a 301. Popup pistons 11 1/2 to 1 with double hump heads. That would get a bucket T, a shoebox or an early Nova to scoot. The Z28 302 was the same idea, with 4 bolt mains or the special racing mains, but you needed 100+octane white pump gas for it to run right. 7500 - 8000 rpm, just like an electric motor.

 

[greyghost]

As the title says, can you make a 305 stroker with a 350 crank and rods?
What would it be? Would it be a 327, or a 340, or is it even possible?
I havent done any research, just dreaming here.
I have a 305 that wrecked the crank and rods, and I have a 350 that is dead, but the bottom end is okay.
Could I potentially put the parts out of the 350 and put them in the 305, and make it work?
Thoughts....

f u have 350 with good bottom, why not just put 305 heads on it? simple and shud not be a headache, as stock 350's had 76cc chambers in emissions era which as far as I know is largest factory chamber made. any sbc intake, exhaust shud bolt up without any major problems for accessories brackets, 3 mt holes front of head dr. side for AC , 1 lower corner for alt. pivot bolt w/spacer, going with older style heads without 3 holes problems arise with mounting Alt. on dr. side without a mounting hole, and aftermarket just not worth money as they create more problems. this situation arose in my 70 SS el camino, w/ dbl hump heads early 67cc chambers bolting to early 327 small journal crank, modifications are endless seems, I have broken 3 factory brackets due to stress on pivot and thermostat housing bracket positions. haven't touch in longtime due to financial bad times, later model engine parts work better together than mixing early with late models.

 

[AyWoSch Motors]

f u have 350 with good bottom, why not just put 305 heads on it? simple and shud not be a headache, as stock 350's had 76cc chambers in emissions era which as far as I know is largest factory chamber made. any sbc intake, exhaust shud bolt up without any major problems for accessories brackets, 3 mt holes front of head dr. side for AC , 1 lower corner for alt. pivot bolt w/spacer, going with older style heads without 3 holes problems arise with mounting Alt. on dr. side without a mounting hole, and aftermarket just not worth money as they create more problems. this situation arose in my 70 SS el camino, w/ dbl hump heads early 67cc chambers bolting to early 327 small journal crank, modifications are endless seems, I have broken 3 factory brackets due to stress on pivot and thermostat housing bracket positions. haven't touch in longtime due to financial bad times, later model engine parts work better together than mixing early with late models.

Wow, that was a while back now. Yeah I've learned way more about all that since.
In my case, the 350 in question broke a connecting rod and it swung around and smashed everything, but suprising the crank looked okay. After closer inspection the crank was a little damaged as well. But the original thought was just put that crank in my old 305 block. After doing research I realized that would be been difficult and a waste of time. I got a nice 350 to put in my truck instead, the other 2 blocks are just good for core charge.

To answer your question, yes putting the 305 heads and intake on a different block would be fine. It's been done. In fact, my 283 has 305 heads and it's a great little engine. But on my old engine the old 305 heads were junk, had 1 cylinder that would fowl plugs because of a bad valve seat I'd guess, and one of the valve stems on the other side was mushrooming over. They wouldve needed to be rebuilt.