1slowbird

Sorry for the noobish question but, I hear solid main windowed mains, I'm looking at 395558 block out of a 69 cutlass and all the pictures I've seen don't look any different than the ones in my 403. I can't seem to find a picture of what solid mains look like. Does anyone have a pic of a solid main 350? Are the mains as solid as the diesel block?

Octania

At long last!
The 403 with main webs like the 395558-2 block!

1slowbird

Sarcasm?

I found a 350 block from a 69 cutlass with #5 heads and I'm wondering if it's worth it. I'm asking because when I look online the pics I find don't look any different.

403

350 (395558-2)
350_zpsqpmowslp.jpg

don71

Look closely between the crank shaft main bearing journals and the bottom of the bores. Those big holes there..those are the windows. This is a 403.

joe_padavano

Every single Olds V8 block cast prior to the 1977 model year had solid mains. Every single Olds V8 gas engine block cast from 1977-1990 model years had windowed mains (and larger 1/2" head bolts) to reduce weight. Diesel blocks were all solid web.

1slowbird

Wow, now I really feel like a noob.
I never knew that's what they meant. I thought it was the area to the left and right of the main caps.
Thanks.
Do you think I should pick up that 350? Guy is asking $100?

Octania

I thing a good 350 core should be worth $100 sure

There is a very long and involved back story to the 403 webs thing, so don't feel too bad. I am the one who decided it was a Myth after offering a reward for many months for even so much as proof that they exist. Maybe search "SMW 403" or "Solid Main Web 403" for more info.

I wanted to chime in but not make you feel too bad and even leave open the possibility that one had finally appeared.

Welcome!

If the 350 has heads, all the better.

after Joe's summary in post #5, as usual with Joe's post, there's not much to add. He nails it.

1slowbird

No problem Octania, I knew the legend of the SMW 403, and even heard about the reward. I was just looking at the wrong area of the block. I just assumed everything I was seeing was a windowed block. Anyways, Thanks for the info.

FrankDMayo

I picked up am Olds 350 engine today. The number on the machine plate is 32M22783 casting F4 on the back behind the flywheel says its a 72 model I assume with the higher nickle metal content. It has the solid main webs. My engine heads are number 7a casting 409147 and engine casting 395558 - 2. The crank has the number 383654. What is the advantage of solid main webs? Being new to Olds engines do the numbers sound like they are original parts ?The motor was reported to have been rebuilt recently with about 5000 miles use after the rebuild. it does appear to have been as the cylinders honing still appears fresh and the valve springs are the heavy springs. I'm looking for about 280-300 hp for my intended application. Thanks Frank.

olds 307 and 403

Yes, the 7a heads are 72 cylinder heads. Does the crank have a big N on it? The solid main gas block is much stronger than the windowed main block, more than people will ever need. What pistons? Stock replacement, big dish cast pistons are no good, too low of compression. Just get the Mahle 10cc dish pistons and a mild cam, easy 300 hp with dual exhaust.

Fpcopo

FrankDMayo

yes it has the Large "N" I don't find my crank number listed but its 3 8 3654 although a 3 93654 is listed as a 350 crank with no N not as a nodular crank. Mine does have the "N" on the first lobe of the crank so I suspect it's a possible 455 crank if its possible to fit in the 350. I'm thinking who ever rebuilt this engine may have hop up the horse power already. Wish I knew what Olds car it came out of originally it'd ne great to put it back in there.

FrankDMayo

I gave the guy 300 dollars for it he was asking 500 but he took 300. I'm hoping that was a good price

olds 307 and 403

What pistons?

FrankDMayo

I don't know I haven't pulled the heads off to see. I can see a number on the cam but I didn't write it down but I can go look.. Maybe tomorrow I'll pull the heads and look at the pistons and see what I can find there.

olds 307 and 403

Good plan, let us know the number on the cam and a picture is best for the pistons along with the stamped numbers.

FrankDMayo

I have re checked my Crank and the number 10 times and I swear the second number is an 8.. but I still can't find it in the engine parts listings. so I'm gonna say it is a 9 but looks like an 8. So my crank is 393654 with a CAPITAL "N" on the first counter weight at the front main bearing which from what i've read should not have the "N" marking it as a nodular metal crank. The piston rods I don't see any number on them so far. The piston itself I assume the markings are on top because I'm not finding any from below turning the engine by hand
.

olds 307 and 403

The crank is more than good enough for your build plans, a nodular crank. The pistons should have numbers on top, if replacements. I am just making sure the 24cc factory dish pistons weren't reused or the even worse 24cc cast replacement oversize pistons weren't used in the build. They have an even shorter compression height meaning less than 8 to 1 compression. The flat top forged pistons will put compression over 10 to 1, not good either. The only passable pistons that should stay are the no longer made 6cc or 14cc cast replacement pistons or the Speedpro LF2321 6cc dish forged pistons. Cutlassefi brought 10cc dish forged Mahle pistons with ultra modern 1mm ring packs and are much lighter as well. They will give low to mid 9 to 1 compression for your motor, perfect. He can also pick a cam to work with your goals.

FrankDMayo

FrankDMayo

FrankDMayo

FrankDMayo

FrankDMayo

Fun71

Sealed Power 332 AP are the big dish pistons described below.

FrankDMayo

I found the pistons

SLP-L2320F30 - Speed-Pro Forged Pistons
at Summit Racing the price isn't bad. I also found the molly rings as well.

Looks like a little change is in order.

Fun71

Go back and carefully read post #18 above.

olds 307 and 403

https://www.summitracing.com/parts/slp-l2321f30
These will work better but they cost less than Mahle pistons for a reason, heavier and thick rings which cost power, fuel efficiency and have more drag.