Junkyard 360 LA Head Porting Questions

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shittyslant6

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I am starting to budget out a simple 360 LA build for my duster so I can know how much money to save. With this, I need a few opinions to help make up my mind. Like the title says, I am getting the engine from a junkyard: pick-a-part, and I am contemplating getting the complete motor (no accessories); $269.00 or just the short block; $195.00.

If I were to get the complete motor, would the stock 360 LA truck heads be worth the trouble porting, polishing and getting milled down? I have heard that the later truck heads crack easily, but I am not so sure they are as fragile as people say.

Or, If I get the short block and pay a little extra for some 340 heads with the same treatment, would the power gains be worth the extra money?

(The end goal for this motor would be to rev to 76-7700 reliably, have 510hp(probably dreaming), and to have 12.5:1 compression(also probably a pipe dream) more like 11:1).

Yes I will have the block blueprinted and balanced, forged pistons, ARP bolts/studs, clevite grooved bearings, and all of the usual oiling mods. I was just on the fence about the heads and the potential power and reliability gains/benefits compared to the price.
 
what year of motor??? If it's the later LA, they'll be 308's and they are prone to cracking, but a good street head if they are not cracked.
 
12.5:1? You are not planning on running pump gas, then? I don't think I would even planning on running pump gas with 11:1 slugs.
 
12.5:1? You are not planning on running pump gas, then? I don't think I would even planning on running pump gas with 11:1 slugs.
holy cow, I didn't read far enough. 510 hp, 7600 rpm spinning 360??? to the op, Never mind my video on 308's.... unless it's just to get it moving temporarily. LOL
 
ummmmm....yes and no. I was thinking a half and half mix of 93 and sunoco 110. (based off a neighbor w/ a 572 hemi dart that runs on sunoco 110.)
But with the reality of 12$ a gallon for that stuff, that would not be the best for driving to school every day. 12.5:1 was a best-case scenario but that number was to give me something to aim for
 
holy cow, I didn't read far enough. 510 hp, 7600 rpm spinning 360??? to the op, Never mind my video on 308's.... unless it's just to get it moving temporarily. LOL

Yeah, those are the "End goal" best case scenario numbers, I am totally ok with 11.5:1 or just 11:1 and 450hp and 7000rpm.
 
I am starting to budget out a simple 360 LA build for my duster so I can know how much money to save. With this, I need a few opinions to help make up my mind. Like the title says, I am getting the engine from a junkyard: pick-a-part, and I am contemplating getting the complete motor (no accessories); $269.00 or just the short block; $195.00.

If I were to get the complete motor, would the stock 360 LA truck heads be worth the trouble porting, polishing and getting milled down? I have heard that the later truck heads crack easily, but I am not so sure they are as fragile as people say.

Or, If I get the short block and pay a little extra for some 340 heads with the same treatment, would the power gains be worth the extra money?

(The end goal for this motor would be to rev to 76-7700 reliably, have 510hp(probably dreaming), and to have 12.5:1 compression(also probably a pipe dream) more like 11:1).

Yes I will have the block blueprinted and balanced, forged pistons, ARP bolts/studs, clevite grooved bearings, and all of the usual oiling mods. I was just on the fence about the heads and the potential power and reliability gains/benefits compared to the price.
Personally, I like factory heads on a street engine; but if you're gunning for 12.5 or even 11:1 and 7600 rpm, I don't know why you're even considering factory LA heads. By the time you add up the machine work, parts (valves, springs, retainers, etc.) and port work necessary to achieve those goals you'll be well within the cost of aftermarket aluminum heads be they TFs, Eddies, Speedmasters, whatever- name your flavor; out of the box with even more potential with a little work to them... not to mention it's easier to run that kind of compression with an aluminum head.
But just so you know, 510 hp and 7600rpm is going to go a little beyond a "simple 360 build"... but I guess your definition could be a bit different than mine. :)
 
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If you could settle with about 400 HP at 5500 RPM you could run pump gas and actually rebuild a 360 to get you there, otherwise your goals mean replacing just about everything with high dollar custom race stuff. Do you want a $5000 engine or a $25000 engine? Why 7000 RPM? Why not 9.5 compression?
 
If you could settle with about 400 HP at 5500 RPM you could run pump gas and actually rebuild a 360 to get you there, otherwise your goals mean replacing just about everything with high dollar custom race stuff. Do you want a $5000 engine or a $25000 engine? Why 7000 RPM? Why not 9.5 compression?

Because I want to keep this engine around and alive for at least 10 years because I cannot afford to do it twice if I blow it up. If I overbuild it, then It gives me room to beat on it and not be afraid of constantly blowing it up and having it sit while I scrape enough money together to build another engine.
 
Because I want to keep this engine around and alive for at least 10 years because I cannot afford to do it twice if I blow it up. If I overbuild it, then It gives me room to beat on it and not be afraid of constantly blowing it up and having it sit while I scrape enough money together to build another engine.
Then plan on sticking with 10:1 compression or less.
 
Then plan on sticking with 10:1 compression or less.

Yeah, that is a more realistic number to go for, considering it is only a 360 and seeing as it could possibly come out of a durango. I just like the idea of a hot street motor to wipe my friends chevy's off the map with. (they are starting to brag about how much better chevy's run than mopar's.)
 
Yeah, that is a more realistic number to go for, considering it is only a 360 and seeing as it could possibly come out of a durango. I just like the idea of a hot street motor to wipe my friends chevy's off the map with. (they are starting to brag about how much better chevy's run than mopar's.)
You should be able to easily squeeze 400+ HP out of a 360.
 
Like others say, go conservative. OEM crank and bottom end of the block won't live at 7,600. Even with W-2 heads on a 360, my old Challenger ran best around 6,800. Didn't see any difference at 7100, so why stress it. Higher compression will be hard on the bottom end too. Look around at proven combos. I ran low 11's with stock valve, unported LA-X heads at 3,540 lbs and under 11-1 flattops in my Dart Sport.
 
If you want a 500hp small block, there are no factory heads that will get you there (atleast not cheap). You are better off with an aftermarket head as a start...then it will need some porting to get there (unless you go with the trickflows).

Mopars are NOT cheap to build like Chevy's....expect to pay at least 2-3x more for your parts (compared to Chevy)....

.....So, now that you have ~ $2500-3000 in heads, THEN you'll need a fuel system to support it, carb that can support the motor, ignition system to support that, suspension that can hold the power, tires that can get it to the ground, frame connectors to keep the car in one piece.....isn't building fast Mopars fun?!?!

Edit: Brakes...I forgot, GOOD BRAKES, lol.
 
I expected the "fun" part of building mopars, that is why my friends consist of welders, powdercoaters, engine builders, and parts hoarders. That is the ONLY way I will able to afford this.


Hopefully...
 
Yeah, that is a more realistic number to go for, considering it is only a 360 and seeing as it could possibly come out of a durango. I just like the idea of a hot street motor to wipe my friends chevy's off the map with. (they are starting to brag about how much better chevy's run than mopar's.)
Durango?? They didn't start building those until, what; 1998 or so? That's no LA, that's well into Magnum territory. A little different can of worms, but they're a great starting point, too. Decide what you're starting with before you start accumulating parts (even in your head), there are some differences that can influence which direction you take.
 
Durango?? They didn't start building those until, what; 1998 or so? That's no LA, that's well into Magnum territory. A little different can of worms, but they're a great starting point, too. Decide what you're starting with before you start accumulating parts (even in your head), there are some differences that can influence which direction you take.

Yeah, i don't really care about durangos, to me they are just cars people get for free and throw away. I am going to get a LA out of anything that has one. probably a d-150 or something.
 
If them chevy guys claim 500 HP, you can probably run with them with a 300 Hp mopar , and run away from them with 400... and you won't need 7600rpm to walk away from them.
 
If them chevy guys claim 500 HP, you can probably run with them with a 300 Hp mopar , and run away from them with 400... and you won't need 7600rpm to walk away from them.
500 hp 383 SBC Nova turn'n 13's in the cool air.... :D
 
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