Hello, got an engine short block, supposed to be a 318. Did some searches but didn't really find the answer. Hope maybe someone can help? On the front passenger side of the block it has the numbers 1737929. Found someone saying that this number is associated with several early Mopar small blocks, 318 being one of them. The front drivers side of the block has LP8-245898 and under that it has 97321 and a star symbol next to it? I'm looking to find some heads for it but wanted to figure out what I have to make sure heads will be correct for it! Any help would be appreciated! Thanks!
318 question?
- Thread starter cawest
- Start date
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Dan the man
Well-Known Member
The engine's displacement is cast on the side of the block.
Professor Fate
Push the button, Max...
Driver's side of the block. Not the front.
Look on the block on the driver's side behind and above where the starter mounts. There will be a casting number and the engine size will be some of the last numbers there.
THAT ^^^^^
67Dart273
Well-Known Member
And also, most SBs actually have a long string STAMPED into the front of the driver side block, right below the head parting line. The first ?? 2-4 figures have the CID coded right into the number, unless it was a rebuild and marked out
Post some pics. Kim
Thanks! I'm not the most computer savvy guy! I got some pics but I'm having trouble getting them from my phone to my computer! The numbers I posted earlier are the only numbers on the block and they are on the front. No numbers what so ever on the sides of the block. There is an A2 on the front of the block also top middle. Pics won't send from my phone to email. Something wrong with email on my phone. Have to get one of my kids to figure it out! lol
I'm thinking Poly 318 block as well. If so is there heads besides poly, like LA engine heads that will work?
Ant
Well-Known Member
You can just post the photos from your phone. Just be logged in FABO on your phone, if it's a smart phone.
Ant
Well-Known Member
Tap "attach photos", then select the photo from your recent photos or Gallery.
If you have Crapple, then I can't help you with that.
Ant
Well-Known Member
I did some research. It's an A block, I think.
Professor Fate
Push the button, Max...
Yeah, that looks like an A (poly) block.
The A has much deeper pushrod reliefs in the block than the LA due to the poly's straighter pushrod angle.
A:
LA:
In addition, if it is an early block, the A may have an additional bolt hole/boss in the bellhousing pattern that could cause some starter interference issues when using a newer transmission. This bolt hole/boss needs to be trimmed off for starter clearance. Later poly As don't have it, though. Can't tell if your block has it, but this is where it would be:
Now the good news.
The poly A block will accept ALL the LA's components. Crank(with 273/318/340 mains)/rods/pistons, cam/lifters/pushrods, intermediate shaft, distributor, oil pump, pan, AND HEADS (although the reverse is not true, poly heads won't fit an LA block without major work). Deck height is the same.
And now the really good news.
With a sonic check just to be sure, poly A engines have been known to accept overbores of up to .130! No, that's not a typo. That's pushing 340 bore territory there. These things are not the LA "thinwall" type castings.
The A has much deeper pushrod reliefs in the block than the LA due to the poly's straighter pushrod angle.
A:
LA:
In addition, if it is an early block, the A may have an additional bolt hole/boss in the bellhousing pattern that could cause some starter interference issues when using a newer transmission. This bolt hole/boss needs to be trimmed off for starter clearance. Later poly As don't have it, though. Can't tell if your block has it, but this is where it would be:
Now the good news.
The poly A block will accept ALL the LA's components. Crank(with 273/318/340 mains)/rods/pistons, cam/lifters/pushrods, intermediate shaft, distributor, oil pump, pan, AND HEADS (although the reverse is not true, poly heads won't fit an LA block without major work). Deck height is the same.
And now the really good news.
With a sonic check just to be sure, poly A engines have been known to accept overbores of up to .130! No, that's not a typo. That's pushing 340 bore territory there. These things are not the LA "thinwall" type castings.
Man that is really great info Professor Fate! That is a crazy overbore! This one was bored 40 over but sat a few years before I got it! Was rebuilt and never used. Had to hone some years of crust out of it but it cleaned up easy and had new pistons and cam, and a steel crank! Re-ringing it though as they where a bit stuck and broke a couple pulling them off to clean up. Spent $200, don't know if that was a great deal but that will sure make it worth a whirl! Knowing I can put LA heads on it will make things easier! The guy I bought it from gave me a Weiand intake for it too! I will look to see if it has the extra bolt hole in the morning! Thanks again for the awesome info!
Bore it to 4" and put a 4" crank in it. Direct drop in.
Thanks Bewy! You may be correct, I wasn’t sure about what cam it had in it so I took it to a machine shop friend of mine and he didn’t know what brand the cam was but he measured the lift and said it was slightly under what a standard LA cam was. Didn’t write the numbers down but he said it was negligible and should not make a difference. But he wasn’t up on what type 318 it was either just that the numbers showed it was an early version! He wasn’t sure of the year!
I’m thinking that back when they built the short block they may have been building a poly and ran into head issues and put it on mothballs or something. Maybe they could not find or didn’t have the heads? Not sure. Guy I bought it from said he bought it in 1998 and it sat in his garage on a pallet since then. So it is kind of a project for me.
It sounds like you could build it as an LA but as cheap as LA 318's are, why bother. You can find LA Teens for $100 or less. Even better yet would be a Magnum with a roller cam. Just sayin.
Professor Fate
Push the button, Max...
Yes, the cam is different because of the different port layout, but the lifter angle remains the same 59* between the A and LA- this is the biggest reason the valvetrain geometry is so screwed up on LAs, and why DC/MP/Ritter etc. released the revised 48* lifter blocks.
@cawest, if you've already got pistons in it (didn't see any in the pics, thought you just had the block) you need to figure out what they are- poly pistons are not compatible with LA heads because of the different valve order, layout and angles used with the poly heads- the valve reliefs are totally different. You will need LA pistons to go with LA heads.
Poly piston:
LA piston:
Flattops with no valve reliefs are also LA pistons.
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