My experience with mass rebuyilder type engiens is you get less than you pay for..Even when they are that cheap. The machine work is 3rd rate, the parts are the cheapest stock replacement stuff they can find, and it is asembled with enough care to get it out of the warranty period. That's it. If you work it at all, it will die very quickly. And by die, I mean maybe not throw a rod, but it will start to smoke, make strange noises, leak like a sieve(sp?), and lose power. They do wierd things too. They dont like to measure or find the smallest oversize to limit stress to the cylinder walls. They bore .060 over when max should be .040, and .040 when max should be .030. They do that because it's easier to bore once way bigger, than do it once, maybe have too much wear or damage to clean up, and have to do it again. because they dont measure for taper, or wear. They also get better pricing when they buy thousands of one size, as opposed to a few hundred sets of each needed oversize. The heads are worse. They dont ever replace valves. Nor do they properly do guides. I keep 2 examples from a cheap Auto Tek longblock on my desk at home. came from the same head. (I still have the "308" cores..lol) One is 1.60, but with a valve job cut. The other is a 1.50 from a 318, also with a cut. Both have the stems trimmed. Not polished..cut, then polished. because it's cheaper to true the stems by cutting, and then using a smaller guide insert, than it is to replace the valve, and replace the guide. both valves were way sunk as far as seats go. The end result..The cutting removes the hardest layer from the valve stem. So it wears out in tens of thousands of mild miles. Remember, it's warranteed for 12 months. The next issue, when it starts to smoke (and not a little BTW...) you pull the heads to have the valve job done. Except, the guides are too small for chrysler type valves. So, you need new valves, and complete sets of new guides, just to get them functional. Nevermind the single cut valve job done (as opposed to 3, 5, or 7 angles being but) and the reusing of trashed valve springs (check out the shim stacks under them to get the tension up and correct the seat sinking)
You'd have better luck finding a running core, and having a reputable shop go thru it the right way. Or even go thru it the somewhat right way, but use the right parts. A good performance rebuild will cost at least $3K around me. It should include every part new except the castings for block, crank, and rods. Those should be completely machined on quality equipment. Then you'll be happy for years, not months.
Stay away from mass rebuilders...
