"Best LA 360 engine"

[AJ/FormS]

I was planning a mild street build.
350-400hp, .30 over bore, double roller, aluminum heads/ rpm intake, 4 barrel carb, mild cam, was thinking of possibly getting a forged crank to replace the cast.

Hey I got one just about like that. She's a honey!

 

[DionR]

I came across a 360 (6-8-74)short block for cheap (6 pack of beer) from a work buddy.

Sounds like a heck of deal no matter what year it is.

But a my dads neighbor claims 71-73 where the "best blocks," I'm just curious to know what LA 360 where the best years. Cause I know that 360's where made of the same 340 mould.

The 71-74 blocks had the same casting number (3418496) and are rumored to be safer to bored out more than the later blocks. I can't confirm it, though. But, to answer your Dad's neighbor, this block should be the same one he feels is the best. And not sure they used the 340 mold, ever, since the crank journal sized changed.

In theory, the rumored greater cylinder wall thickness of the first generation blocks would make for a better foundation, but I've never seen anyone complain about the later blocks.

Really only 3 different LA 360 blocks I can think of, early (71-74) with a thicker cylinder wall, later with a thinner cylinder wall and ones with provisions for roller cam followers (and thinner cylinder walls). So "best" almost seems like a personal opinion rather than a flaw in some blocks (unless you count the lack of provisions for the roller cam followers a flaw).

 

[rumblefish360]

the 1971 360s had a little more compression due to a a slightly better piston. the 1974 360 HP WAS COOL with the 340 cam, windage tray, double roller, 850 thermoquad, the late 360s are cool if U want to go roller cam-taller lifter bores right. unless U are going 600+ horsepower any year will do fine. "ballad of the uneasy rider" mag wheels and 4 on the floor had gravel flying and rubber squeelin

the only thing missing was compression and 2.02's. LOL

My questions would be:

1. Best for what?

2. What do you wish to do with it?

Those should also be the questions you ask yourself.

EXCELLENT QUESTIONS!

I was planning a mild street build.
350-400hp, .30 over bore, double roller, aluminum heads/ rpm intake, 4 barrel carb, mild cam, was thinking of possibly getting a forged crank to replace the cast.

The cast crank is fine. They can hold a good amountof power and since your in the street, you'll basically never have to worry, so long as you do not abise it, just like any other engine. If you were to build a 575+ HP track car, I would suggest abit more than a forged crank over the stock cast.

The 71-74 blocks had the same casting number (3418496) and are rumored to be safer to bored out more than the later blocks. I can't confirm it, though. But, to answer your Dad's neighbor, this block should be the same one he feels is the best. And not sure they used the 340 mold, ever, since the crank journal sized changed.

In theory, the rumored greater cylinder wall thickness of the first generation blocks would make for a better foundation, but I've never seen anyone complain about the later blocks.

Really only 3 different LA 360 blocks I can think of, early (71-74) with a thicker cylinder wall, later with a thinner cylinder wall and ones with provisions for roller cam followers (and thinner cylinder walls). So "best" almost seems like a personal opinion rather than a flaw in some blocks (unless you count the lack of provisions for the roller cam followers a flaw).

Dion, I find this post dang near excellent! I really do. It is the truth. I typed these words before, "Excellent prep/machine work" on what ever your building is worth more than the supposed super block you paid extra for.

The less you overbore the block, the stronger the cylinder walls will be. Less flex. Better sealing. Bore and hone woth a torque plate on top. Keep overbores to a min.! At .030 over bored, you can a whooping 5 cubes! BIG WHOOP! That is nothing.

I high lighted some of Dion's reply. The rumored thick walled blocks, can also be found in later years. Why I don't know. But it should not matter if the above is followed!

 

[krazykuda]

The best 360 is a free one that still runs...

 

[Abodybomber]

The best 360 is a free one that still runs...

This.. If it's reringable ,do it. You can bolt on Edelbrocks,aluminum clones,...With a mild 225-230 @ 050 cam,will get you there. ( on the cheap down low..) add a 2500-3000 stall (a good one..,depending on your cam choice ,a Road Runner spec'd converter(12 inch,2000-2200 stall,factory parts..) just might do it... Whatchya got ,for rear gear & tire diameter?...

 

[gilberttitan08]

This.. If it's reringable ,do it. You can bolt on Edelbrocks,aluminum clones,...With a mild 225-230 @ 050 cam,will get you there. ( on the cheap down low..) add a 2500-3000 stall (a good one..,depending on your cam choice ,a Road Runner spec'd converter(12 inch,2000-2200 stall,factory parts..) just might do it... Whatchya got ,for rear gear & tire diameter?...

I got a 8 1/4" 3.55 sure grip. Not sure on tires yet.

 

[ch1ll]

yeah the 71-74 blocks had thicker cylinder walls cause Chrysler used the same 340 patterns to cast the blocks with minor changes to the patterns to use a larger journal cast crankshaft. matter of economics in changeover tooling from the 340 to the 360. later than 74 they thinned the walls to save weight and use less material($$$$). 1975 was a big year to meet government gas mileage requirements.

but still sonic checking for wall thickness is best to determine a sound block and proper machining practices are the way to go. only overbore if needed and go as little as possible. you might be able to get away with a rehone.

and at 400 hp or less, any year block and the stock crankshaft will be fine.

if I were you, I'd spend my spare money in a good auto machine shop and on parts to give it specific performance characteristics, cam, valve train, heads and the such.