Just tore my 383 down to get the springs swapped out on the 915's. Found out my piston on this 69 HP 383 is .080 in the hole. (No surprise there)

My 915's are in amazing shape. Already had hardened seats installed and minor clean up. Stout heads for sure, and they haven't been cut.

The block is pretty worn, but has been running great with minimal blow by for the years that I've had it. The bore is pretty worn up to the top ring area and the ridge is significant.

My buddy who has been building cylinder heads and engines for 30 years suggests a KB 400 @ .030 over and button it up with fresh rod bolts and bearings. I could get it built at WD pricing....so no complaints.

The heads will get cleaned up and reinstalled with good springs.

So, do I pop my new cam/lifters in with the fresh heads and let it keep ticking away or do I freshen it up and build a real 10:1 383 with a little piece of mind. I've got a whole other machined 440 block minus rods and pistons but I'm not ready to start a motor from scratch.

I'm worried about the 383 letting loose and destroying the heads if I don't fix it now.

I don't want a ton of power out of it. A properly built 383 would do me well for many years. On the other hand, I don't drive it much any more due to work/school/life. Should I button it up and just let it be until I can built a more stout engine later ?

I've never seen a 383 let go even with the loose bores and everything else. I know they're stout. Should I be worried about a worn out 383 letting go on the street ?

Rebuild the 383 ? single choice
	Leave the shortblock alone. It won't hurt itself.
	KB400's@ .030 over, bearings and run it with no worries.
Votes accepted starting: 10/15/10 07:41 PM
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I'd check/replace the timing chain, fresh oil pump, check the bearings for wear, and put it back together. Save the money for the 440 if that is the final goal.

You mention the ridge at the top as being significant. Do you think it will clean up at .030 or will it take more than that? My brother bought an engine out of a wrecking yard and the ridge didn't look too bad, but when he took it into the shop they kept cutting and the top ridge on a couple cylinder bores never went away. Once they got to the .060 over rough cut they called and told him to bring them another block.

If you do bore it have it measured before buying any parts.

The ridge starts at 4.250 and goes out another .025+ from there. It's worn. My buddy hasn't touched a BB mopar since the early 80's and he was just giggling to himself from it all.

We pulled a ranom main and rod bearing and both look good. The engine drove pretty strong considering it was overcammed and had MP manifolds. Putting a smaller cam and headers on to make it a little more efficient.

A healthy 383 is a great engine. I'd do the basic rebuild and keep it going strong. With a healthy engine you will enjoy driving it and taking care of it also.

Have you cc'd the heads to see what they are ?

Go with a stock bottom end 383 and then add the good bits to it. You will have power and reliability that will last you for years

Buy a cheap rering kit plus a cam/lifters for several hundred w your current over/under size of rings/bearings (most likely std). Rent a ridge reamer & pay someone who knows how to properly use it (pull the cutter toward you dont push it and dont remove all the ridge). Different opinions on this but I would suggest Moly rings (several $$ more) and read "breakin secrets" at www.mototuneusa.com (5 minute read). You'll be set for quite awhile until you get your good eng going.

Stroke it!

Personally I wouldn't put any money into it.. Pistons .080 in the hole = low compression.. .025 wear at the top of ring travel.. It's worn out.. Patching it is a waste of money, either a full performance rebuild or save you money for the big engine & run what you have till it won't run no more.. You've eyed the bearings, it won't go boom, just old & tired.. At 1000 miles per year it'll last five years easily...

I agree, leave it. At most, do a hone'n're-ring with a new set of hastings cast rings and a drill mounted hone/deglazer. Rings + HV oil pump, hd intermediate shaft, 7 quart oil pan, cam, headers, heads and intake is what I did to my tired 70's smogger 440 and it real pretty good for what it was. Nothing ever let go on it.

slap in the cam,some fresh gaskets,a good bath and some paint,go on and add a HV oil pump,and run it. with no more miles than you are going to drive it,it will last a long time. save your pennies for that future 440. if she ain't blowing smoke,eating a bunch of oil,or has a bunch of bottom end clatter,i'd say run it.

hummm at .080 in the hole a little boost would go a looooooooong way.

Put some cheap rings in it and let'er rip! A loose motor is good for a little drag'n action..........