1998 5.7 Rebuild or Replace at 235,000 Miles

I realize there are many factors that can influence answers to this question but here it goes.

Due my own negligence of not repairing my radiator I have overheated the engine a few times so yea, dumb ass to start with and I believe I have had a minor head gasket leak for sometime that is now major due to the last over heat. The dealership diagnosis says either a severe blown head gasket and/or cracked head. I have done another dumb ass move and added water to a hot engine low on coolant so a cracked head could be a real possibility.

Currently coolant(water mainly) is getting into the exhaust but no coolant is really getting into the oil. There is evidence of residual moisture at the oil fill cap but nothing anywhere else really that suggests that any major moisture getting into the oil at all. There isn't any abnormal knocks or ticks coming from the engine when running and the oil pressure seems to be normal. There was however a good bit a gunk sticking to the oil drain plug magnet when I drained the old overheated oil.

Due to the mileage the dealership will not tear down the motor to replace the head gaskets or heads if required and they have suggested a new engine. A co-worker says he could rebuild it with a master engine re-build kit and machine shop help from some acquaintances around town for a reasonable price.

The rebuild would for sure be cheaper but could take weeks to complete whereas the engine swap could be done in a few days. I only have a motorcycle as a back up vehicle so a few days is very appealing during this rainy season but is it the wiser choice? It is expensive but would give me many new OEM components and a 3 year GM warranty. The rebuild could be a crap shoot. Another option I guess would be a having an independent shop quote me the same as the dealership. That alone would probably save me a bunch of money but I may not get the same type of warranty.

Ultimately though; would a rebuild be a fair consideration at 235,000 miles and possible heat damage or would I be better off with a new engine and warranty?

The rest of the truck is in fairly decent shape so I have no concerns of anything else major really needing to be done. Transmission was rebuilt about a 1-1/2 years ago.

do not go to dealership with a vehicle this old ... having had many coolant issues with your lack of quickly properly handling this the best thing to do if the body/drive train is in good shape I would get a scrap yard engine . you should find many at the yards . after you find motor replace , all the defective coolant system components flush the system out . use 65% coolant to 35% distilled water DO NOT USE TAP/WELL WATER ...REPLACE PRESSURE CAP. HAVE A LOCAL repair shop install engine that has experience with this.

Found a used 5.7 caprice police car engine from a fairly reputable source. My co-worker knows the guy so he will be able to check it over prior to it being installed. He says he will check the compression and remove the lower pan to inspect the bearings. Hopefully all is well with it and I can have my truck back on the road in a week or so. Even if it needs a little rebuilding it will still be much less expensive than the new engine route.

I really couldn't bring myself to pay that much for a new motor. Especially with two kids in college. This was a much easier decision after finding this engine.

If this is an LT1 350CU I would not use it. find a 350cu truck engine. the LT1 uses a much different system of electrical timing controls. also different fuel pressures .. with the correct 350cu truck engine a very low cost swap...

Ditto on the LT-1. Besides ex police car engines have a lousy service life overall. High mileage, excessive idling times, severe performance demands, slip seat drivers who don't really give a crap. Find a 350 cu, 4 bolt main truck engine as suggested.
First find a dependable shop through recommendations that does this kind of work. Tell them what type of engine and what not type of engine you're looking for. If they're good they will take an interest in what you're trying to accomplish and assist you on engine procurement with some kinda warranty as well as warranty on their work.
They'll probably suggest some maintenance upgrades to the new engine prior to installation,(new water pump,timing chains,gears,oil pump etc). Come to a price and have it done.
Don't go for fast turn around...you'll regret it. A lot of shops make promises they can't keep just to get your business. You might wind up riding your bike anyway with an unfinished or unreliable car still in the shop. HTH

My co-worker who is now ultimately doing the majority of the work has suggested that since he'll have the existing motor out anyway he will look it over and access the possibility of rebuilding what I have prior to jumping into the caprice engine. He knows where he can get a used set of heads if need be so this is the route I am now taking. Baby steps for now until we can get the current engine pulled apart and see what we have to work with. A rental car has eased my urge for the quick fix. In the end I believe my co-worker will get this done the best way possible for me.
I appreciate everyone's input. Thank you very much.

perhaps I did screw up a little with this LT1 not being used .

this LT1 is not compatible with your PCM/electrical system. now some may want this type mod to be done . well if you have much free cash to blow go for it.

as I and others suggested get a scrap yard truck engine plug and play except the cooling system work. fastest and cheapest.

235K on an engine you re-build it it will cost much more than the scrap yard and many more issues... it will be like a jack in the box....

235K on an engine you re-build it it will cost much more than the scrap yard and many more issues... it will be like a jack in the box....

I'm curious as to what issues you think I may encounter by re-building verses scrap yard. Once re-built shouldn't it then be in very good condition? I'm thinking one never really knows what your going to get with a scrap yard engine.

You said your engine had been severely overheated several times and you added water to a hot overheated engine. Right there is why I'd rule out overhauling it.

I'm curious as to what issues you think I may encounter by re-building verses scrap yard. Once re-built shouldn't it then be in very good condition? I'm thinking one never really knows what your going to get with a scrap yard engine.

you can find a 100K engine that is fully compatible with your vehicle. many truck 350cu engines are out there. scrap yard , a good one , will not screw you , if the motor is bad. motor change out is not expensive. some yards will do this for you also .

as you found 235K engine failed. many that take better care get much more. depends on how much work the truck is doing.

rebuilding a 235K worn abused motor is not a good idea.............