Chrysler LA / NASCAR 355 cu. in. crank shaft

[greymouser7]

I recently purchased a lot of Chrysler parts from a guy who claimed his grandpa was a NASCAR racer. Looks like a have a 355 cu. in. crankshaft for a small block LA. I have another crank that looks just like it that came in the lot i purchased, but I can not confirm its specifications yet.

What do I do with this crank? I really don't have a use for it. What's it worth? Who can use it?

View attachment 1715827441

View attachment 1715827442

I am going to go out on a limb with my imagination here. :
1. That stroke is similar to the SBC 350.
2. People here, including me have purchased connecting rods for mopar cranks with the chevy wrist pin size on the small end. This could open up some piston options, like for example the 327 chevy piston which has a similar compression height to the mopar 360 piston (now both engines would have the same rod length. Chevy pistons would give you a chance of many options. The way the valves lower is a consideration regarding piston selection while thinking of valve reliefs and valves contacting pistons.
3. that leaves either a late 60's early 70's 318 block bored all the way out .090" or maybe a 327 + .040" or + .060" piston with a 340 block.
4. Additionally, allot of enthusiasts have purchased LOW DECK R Blocks where a crankshaft such as this would be much more optimal in any attempt to match rotating assembly length to block height.
Good luck and GOD bless

 

[Rat Bastid]

I am going to go out on a limb with my imagination here. :
1. That stroke is similar to the SBC 350.
2. People here, including me have purchased connecting rods for mopar cranks with the chevy wrist pin size on the small end. This could open up some piston options, like for example the 327 chevy piston which has a similar compression height to the mopar 360 piston (now both engines would have the same rod length. Chevy pistons would give you a chance of many options. The way the valves lower is a consideration regarding piston selection while thinking of valve reliefs and valves contacting pistons.
3. that leaves either a late 60's early 70's 318 block bored all the way out .090" or maybe a 327 + .040" or + .060" piston with a 340 block.
4. Additionally, allot of enthusiasts have purchased LOW DECK R Blocks where a crankshaft such as this would be much more optimal in any attempt to match rotating assembly length to block height.
Good luck and GOD bless

You have to correct the valve notches if you use chevy piston. Chevy valves don’t open on the centerline of the bore and the valve angle is 23 degrees and the SBM is 18.

 

[greymouser7]

You have to correct the valve notches if you use chevy piston. Chevy valves don’t open on the centerline of the bore and the valve angle is 23 degrees and the SBM is 18.

Yeah I knew you had to check them, am wondering if they make pistons for their 18 degree heads. Rat you have decades more experience than I do, but I bet YOU could find something in summit webpages, with 1/24th the time of porting the first intake runner of a 302 head!!! ROFL

 

[NoCar340]

The '72-'73 340 piston had a 1.740" compression height. With the 3.454" crank that started this thread, that's .010" down on a 'factory' 9.6" block height, or the same amount above on the common 9.58" blueprint height.

The Sealed Power forged piston part number was L2385F, but it's been dodo for years. I'm not aware of anyone making a '72-'73 replacement piston at the moment.

 

[dirty white boy]

You have to correct the valve notches if you use chevy piston. Chevy valves don’t open on the centerline of the bore and the valve angle is 23 degrees and the SBM is 18.

theres 18 degree chevy pistons out there, idk if notches on center line or not tho...

 

[Rat Bastid]

theres 18 degree chevy pistons out there, idk if notches on center line or not tho...

I believe the 18 degree stuff is on the bore center. You just can’t get valves that big in the bore if they don’t open on the bore center.

 

[dirty white boy]

I believe the 18 degree stuff is on the bore center. You just can’t get valves that big in the bore if they don’t open on the bore center.

do people angle mill sbm heads like every body dose sbc heads? i know in dirt track the fords are 9 degree head,...ive seen chevy 23 on down to 13 but 13 degrees didnt work good on them bow ties

 

[Rat Bastid]

do people angle mill sbm heads like every body dose sbc heads? i know in dirt track the fords are 9 degree head,...ive seen chevy 23 on down to 13 but 13 degrees didnt work good on them bow ties

Yes. It’s way more work than people may realize but it’s done.

 

[Bakerlite]

That was just rude …
Those were the cars they grew up with and are just as precious to them as our versions are to us . And the Aussies do a lot for our sport in the way of development. They got some fast ****’s down there !

I should know, I live in Australia. The Mopars here were always the least desirable performance cars.
Their idea of a big hitter was a 6 cylinder. An engine they called a "Hemi" when is wasn't.
Compared to their American cousins, they were lame..

 

[mbaird]

I should know, I live in Australia. The Mopars here were always the least desirable performance cars.
Their idea of a big hitter was a 6 cylinder. An engine they called a "Hemi" when is wasn't.
Compared to their American cousins, they were lame..

Still its not ours to say . I wouldnt bash a /6 Toad just because I like 340s and bigblocks .

 

[Bakerlite]

Still its not ours to say . I wouldnt bash a /6 Toad just because I like 340s and bigblocks .

LOL,.. yeah, well I'm saying it, and I guess you have to live here to understand it.