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Looking for 360 Build Ideas

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CamJam View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CamJam Quote  Post ReplyReply Direct Link To This Post Topic: Looking for 360 Build Ideas
    Posted: Aug/06/2022 at 11:48pm
I'm trying to decide which way to go with my '73 Javelin 360.  The unmolested stock engine runs fine, but at 114k miles it seems a little tired, and I want to pull the engine and tranny anyway to paint and detail.  Among the things I've considered are swapping in a 5.7 hemi, but I must admit a bias to keeping the original 360.

I'd like to try to get about 400 hp out of the 360.  What would be the most cost-effective way to get there and still be able to run on 89-91 octane pump gas?  I live at an elevation of 3,400 feet, so might get away with running a bit more compression.

Just looking for a nice performance driver, but reliable enough to drive all day at 75-80 mph in case I ever choose to drive it across the country.

Would be great to hear some thoughts on this from those who have been there already.


Edited by CamJam - Aug/07/2022 at 12:08am
'73 Javelin 360 (current project)
'72 Baja Bronze Javelin SST
'69 Big Bad Orange AMX (2018 Teague Heritage Award) SOLD

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Post Options Post Options   Thanks (0) Thanks(0)   Quote PROSTOCKTOM Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 12:48am
You're asking a lot to get 400 HP  out of a 360 using mid grade gas @ 3400 ft. elevation.

Easiest way is refresh what you have (rings, bearings, gaskets, valve job) and put some type of forced induction on it. (Procharger or similar belt driven power adder) 5-6 pounds of boost and you'll be there.

Tom
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jcisworthy Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 3:37am
Ported factory heads, fairly aggressive cam around 220 @ .050 intake, air gap gasket matched and blended, plenum divider notched, 10:1 cr, headers, 750 carb 




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Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 3:52am
I’m getting on board with Tom, forced induction. I’m working on a little 318 Mopar build at the moment and the original plan was to add some compression, lumpy solid flat tappet cam and do some work on the heads. I’m really starting to rethink this whole thing, by the time you add a decent set of pistons, maybe rods, have the thing balanced, new cam and lifters plus all the other run of the mill stuff, the dollars soon mount up to a lot more that what I really want to spend. I’m now thinking, why not take advantage of the low compression, I can just re-ring the thing and add a cheap eBay turbo, probably make more power and be way cheaper, might not even need to change the cam. It has had a mild performance build previously, so some stuff is already done.

Edited by WesternRed - Aug/07/2022 at 3:55am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jcisworthy Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 6:34am
Been thinking about power adders myself. Mild cam, taller gears and let the power adder do the work

Forged pistons and rods would be a minimum for me using a power adder
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 7:34am
Forged would be the go for durability, but I think you could get away with cast bits so long as you don't go too crazy with the boost.

If staying N/A, then the old 343 flat top pistons are a tried and true low budget way to get a bit more compression into a 360.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Buzzman72 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 7:59am
Something not addressed, but which should be, is switching to an overdrive transmission. Whether an automatic or a stick, if you want to run 75-80 MPH on the interstate and still not have a "slug" around town, o/d is a must. It can be like having your Kate and Edith too. [Bad, bad joke.]

Of course, your cam will determine where your engine runs "happy," but I prefer not having the rpm above 3000-3200 on the interstate because I don't own oil company stock.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 9:02am
Going with John on this, using the kiss principle.
The Wiseco forged pistons -21cc will bring you to 9.1 SCR allowing 60 cc cleaning up the combustion chambers.
Cast heads that need to flow 250 @ 0.550, Chev 7/32 valves will help achieve this flow. 90% throat on the intake and 85% throat on the exhaust. You want maximum gas velocity at 0.400" valve lift. Edelbrocks will do if you cannot do the porting.
Just off the top the Lunati 10100702 will provide 7.78:1 DCR.
Airgap intake.
410 to 420 HP @ 5400 RPM.
Also would suggest an overdrive transmission.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CamJam Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 10:00am
Just remembered that I have a lightly used set of 343 4V pistons sitting here, P/N 3182689.  Tried selling them at Kenosha last week but no takers.  Would they give a workable compression ratio in my '73 360 with stock 58cc heads?  Maybe too much compression with Edelbrock heads?

91 octane is about the best we can do around here on pump gas.  93 octane more common in some areas along the Colorado River and Lake Havasu where they're at low elevation and have a market for lots of racing boats running V8s, but that's about three hours from here.

Overdrive transmission might be part of this build too.  I have an AW4 in one of my cars already.



Edited by CamJam - Aug/07/2022 at 10:16am
'73 Javelin 360 (current project)
'72 Baja Bronze Javelin SST
'69 Big Bad Orange AMX (2018 Teague Heritage Award) SOLD

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Post Options Post Options   Thanks (0) Thanks(0)   Quote ericdowneast Quote  Post ReplyReply Direct Link To This Post Posted: Aug/07/2022 at 10:37am
I like the 702 cam idea but isn't a little too much lift for the bridged rockers without modification?  (Assuming the lower comp heads are bridged rockers)
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