78 401 build advice

I've got a 78 wagoneer with a 401 and its got the Quadratec 4wd system, I am looking on some advice on how to build my 401. Its completely stock at the moment and runs great but I can tell its getting a little tired and with the quadratec it doesn't have too much power. I'd like to build it as a weekend trail rig but still reliable enough to drive around town and occasionally take some 100+ mile trips. I plan on doing a full rebuild on it this summer and am looking to spend close to 3k on it, I figure for the moment I plan on doing cam, intake, carb, headers, HEI ignition, possibly boring out not sure if I just want to hone the cylinders or bore them, Aluminum heads if money permits. Any advice on the brands and what not I should get would be greatly appreciated.

It's going to go a lot more than $3K if you even think about boring or aluminum heads. Boring the cylinders is going to require new pistons. You won't know if you need a bore until you get the heads off and Measure the cylinder taper. If taper is out of spec, then you need a bore. If you hone and re-ring an out of spec cylinder, it won't last long and you'll be doing it again.

Just for a reliable, street friendly rig, I'd keep compression under 9:1 (factory is 8.25:1). You can bump compression some by milling the block and heads, or going to aluminum heads. Cam - I would keep duration in the 270-280 range, 110-112 lobe center for a smoother idle, and lift under .500". The Edelbrock Performer is a great all-around manifold, and you probably want to keep the carb to 650 CFM or less with vacuum secondaries. If you have the Motorcraft distributor, it's a good piece. You can adapt it to a larger cap and wires using Ford pieces. I don't care for the GM HEI conversions. Oiling on AMC motors is important. Inspect the oil pump cavity. If there's any deep scoring or heavy wear, replace the timing cover. If it's serviceable, Then go with the HRC pump gears and a mid-plate available here at Bulltear. Be sure if you have the crank turned that they go by AMC specs. A lot of machinists go to Chevy specs, which are too loose for AMC engines and as a result they have poor oil pressure.

Bob
tufcj

Awesome, thanks for the info. I've already replaced the oil pump and used the midplate when I bought this a couple months ago. Oil pressure was sitting about 20psi at idle warm. Now its up to about 60psi cold and sits about 40psi when warm. I'm assuming there is a spec sheet around the website here for the crank? As for the aluminum heads I may just skip those since they are pretty pricey, I might just see what I can do with the factory heads to make the engine breathe a little better.

You should be able to find a TSM (technical service manual) for a 78 Jeep pretty easily, either in reprint or used. All the specs are there.

I have over $3K in my last 390 build. I bought all the parts, had a local shop bore, turn the crank, port/polish the heads (with a 3 angle valve job), and balance it. I did all the assembly work. That engine is in my 67 Rogue right now, but I haven't started it yet. I built the engine that's in my AMX, it was built with the best of everything to take a 150 shot of nitrous. I put well over $5K into that one 12 years ago.

Bob
tufcj

Thanks, BJsoffroad probably has a manual for it, I'll have to grab one of those. That's what I planned on doing is having a local shop do all the machining and I can handle the assembly part. Now I just have to wait till summer/spring to roll around so I can start tearing into it.

If you're still thinking aluminum heads, Amazon had them yesterday for $809 each. Cheapest I've ever seen them. Free shipping too.

Bob
tufcj