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Old 08-12-2017, 09:01 AM
Maurice66 Maurice66 is offline
Join Date: May 11, 2015
Location: Iowa
Posts: 2
Engine rebuild questions

1978 Cherokee Chief. 185,000 miles,4 speed with lock outs. 360 in the shop and needs a new cam, over sized pistons (.10),guides and a couple valves. Not to bad. Question: This is going to be a cruising rig, trail riding(?), highway and towing my military jeep. So is there any improvements I can make while its being rebuilt to improve fuel mileage, reliability and maybe add a little HP? Also is there any inheritance issues with the engine,transmission,transfer case and diffs that I can take care of while the engine is out of the vehicle? Its mostly original. The ignition is Motorcraft and the carb is also Motorcraft. The inside is totally gutted. OK I am rambling, you get the idea. Thanks for your help!
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Old 08-12-2017, 09:29 PM
440sixpack 440sixpack is offline
Grease Monkey
Join Date: Jul 21, 2016
Location: oregon
Posts: 329
For all practical purposes higher compression pistons are where it all starts. how much fuel economy are you willing to sacrifice and how much money do you want to spend? that is what you need to decide and then you can make a plan..

I rebuilt my 360 with a mild cam upgrade and pistons to put me in the 8.5 to 1 range and kept it pretty much stock. I'm not headed to the drag strip so this works for me.

As far as the rest of it goes you say it has 188 k on it . that in itself means you should be planning to rebuild everything in the not too distant future upgrades or not. Your TH400 has no inherent issues, your axles don't either. but they wear out.
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Old 08-13-2017, 01:51 PM
Ristow Ristow is offline
Join Date: Jan 20, 2006
Location: The Great Googley Moogley Midwest.
Posts: 16,694
put cam bearings in it. the performer grind is the best cam for a stock block,it'll make the most usable power in the transmissions shifting range.

dual exhaust,and long tube headers as well are a big help.
Originally Posted by Hankrod
Ristows right.................again,

→ Where the kids hang out... come for the mindless chat,stay for the hand drawn emoticons.

It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...
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Old 08-14-2017, 06:43 PM
Maurice66 Maurice66 is offline
Join Date: May 11, 2015
Location: Iowa
Posts: 2
Thank you for your replies. Good stuff. Another question: What about all that emissions tubing? Can I eliminate all that without affecting the engine performance? I mean will it idle and accelerate OK without it? I want to just get to the bare necessities. Is the Motorcraft carb OK to rebuild or do you suggest another? What about the ignition system? I heard it is suspect? Thank you for replying and helping a noob out!!
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Old 08-17-2017, 06:29 PM
BA_051 BA_051 is offline
Join Date: May 06, 2008
Location: Everett, Washington
Posts: 136
Personally, If i was to build a mostly stock 360, I would put amc 343 flat tops in it with a melling MTA-1 cam, or the performer cam, both are very similar grinds if not the same... anyway, back to the specs...

4.08 bore plus 0.010 overbore
3.44" stroke
5.875" rod length
with the performer or melling cam, intake closes 27 degrees ABDC...
compression ratio:
343 4 barrel pistons are 4.0cc flat top
343 2 barrel pistons are 12cc flat tops (so it seems)
stock, low comp 360 pistons are 28cc
Heads (Im assuming 1974+ are 58cc heads)

static compression ratios are 10.82:1 with the 4 barrel 343 pistons and 9.87:1 with the 343 2 barrel pistons...

Dynamic compression is where its at... With the melling/performer cam, the dynamic ratios are 10.42:1 with the 4 barrel 343 pistons, and 9.46:1 with the 2 barrel pistons.

9.46:1 can run on regular pump gas just fine, the 10.42 may need mid grade... My stroker was 11.6:1 static, 10.2:1 dynamic and i could run it on regular, but I lived at 5000-7000 ft... For just a daily driver, I would recommend the 4 barrel 343 pistons.

As for other upgrades... Run some nice long tube headers... the Motorcraft distributor is ok but do the TFI upgrade or run an HEI... And put on a performer intake and 4 barrel carb. Get rid of all the emissions, your motor will thank you. The motorcraft 2b is decent, but an edelbrock or holly 4 barrel, 500-600 cfm will really wake it up especially with headers and higher compression.
1974 Jeep J10, gladiator grill, 6.5 optimizer, head studs, HX35w@ 20psi, 4" exhaust, NV4500/Ford NP205, D60HP, 14b, 4.56's, 12" lift, 37x12.50x16.5's

Last edited by BA_051 : 08-17-2017 at 06:35 PM.
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