help with my 86 chevy C 10

the truck has a 350 four bolt main with performance heads and performance intake,headers and a holly four barrel.this was bought as my son`s truck and it`s been painted traffic ticket red,new wood in the bed and the inside redone.O.k. to my problem, when i went on vaction i can home and the truck wouldnt start,barely would roll over.i checked the battery,plugs,coil,rotor,cap but still it wouldnt roll over fast...checked the oil and found gas was in there.(i think while i was on vaction my loving son made some adjustments on the carberator),,,,so i pulled the starter and had it checked ,its good.then i pulled all the spark plugs,drained my gasey oil,put fresh oil and tried to get her to roll over without plugs ......she makes it about a half a turn and binds up.then i put a socket with a pry bar on the crank and could roll it about3/4 the way before it binds up again.........................BLOWN MAIN BEARING HUH.....do ya`ll think that this is the cause??? ,i havent broken into the motor yet because i`ve been working nights...i would love to save my heads or is it even worth looking at them any way..my first post is about a blown motor question,sorry......please help i`ve already priced a replacement 350 with 300hp(block,heads) for about 1400.00.. thanks for all ya`ll help:

what are the casting's on the heads? if there aluminum or an aftermarket head, even a vortec there worth using on the new motor.

i`m at work so i can`t look,heck where do i look and then how do i I.D. them..(look them up)sorry about this i`m out of practice my firist car was a 70 road runner,untill i had kid`s,so i`ve been driving suv`s and van`s for awhile,hey kids are grown i bought a 2002 z28 and this nice truck for my son(17) believe me i need all the help i can get.if the main is blown can the heads be salavaged............is it the main or maybe the tranny some how.that other 350 with 300hp was going to be built by periscion auto in houton there the best in town,i would get block thru valves,use my valve covers and intake ,carberator,oil pan. etc

the castings are in the rocker valley, if there aftermarket they may not have a casting so keep it anyway, but if there is a GM cast in the head, it is a stock head and u could go to mortec and decode the casting.

what do you think of the main bearing ?could it be something else...i know i need to look just trying to get all my options.if gas was in the oil while driving everthing is probaley shot......that`s what i`m thinking,not enuff lube on everything just thin gasoil

can u crank it over all the way smoothly without binding, by hand using a ratchet? my grandfather had/ has a '67 GMC K25 ( 4spd manual ) that my dad and him put a 350 in, and it ran, but started extremely hard due to the incorrect bell housing and it had a lot of resistance, took 2 battery's to get it to turn over fast enough to start, otherwise it would go over once or twice and bind. my thinking is the flex plate could be bent or loose, causing hard starting and binding.

That reminds me of the time this kid took his dads truck to the track ,while his dad was out of town.He made it down the track and blew the engine.Parts and oil all over the track.:CRY:

no when you turn the motor over,and its gotten worse it drags at one spot.flex plate sounds a little better than a main bearing but i have a auto trans.. any more ideas or guess`s are more than welcome !!!!!!!!!!thanks

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Originally Posted by BigTruckDriver

That reminds me of the time this kid took his dads truck to the track ,while his dad was out of town.He made it down the track and blew the engine.Parts and oil all over the track.:CRY:

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well it was backed into the driveway at an angle..........hummmm maybe tow truck ???? had to park my car in the street...

when u said gas in oil is that an oder or very strong smell ? because carb running engine dump more gas than needed and makes its way past the rings that dont burn in the cylinder. A brandy new crate motor will do this. u will always smell gas in the oil. And when u crank the motor by hand with a breaker bar and u hit the compression stroke it is extra hard to turn. do u hear any metal or knocking when u do this by hand at the point it stops at. i would check the battery by taking it out and getting and another one out of your suv and see what it does. did u find any metal shaving or chunks in oil when u drained it? 9 times out of 10 something will be in your oil when it lets go.

swapped battey first thing,we took all the spark plugs out so we could try and spin it easy without compression,no luck...the oil looked more like dirty gas then dirty oil and i havent opened up my can and looked for metal yet.i`m hoping ya`ll can give me some clues where to look and the car engine fairy will some how bless it ,so it`s not the main bearing 1 gooo steelers been a fan since the 70`s the motor was suposed to be out of a late model corvette soo i realy want to save the block,without taking out a second morgage

well if u dont see anything on the plugs such as shavings when u pulled them. You'll have to drain oil again and pull pan off to see if its the bottom end. Whats your fly wheel look like is it chewed up at all? pull the drain plug let it sit a day or 2 let the oil get off the crank real good pull the pan. try to get your kid to rotate the crank while u inspect

what about the heads, what are the chances they made it out alive,got any quick check ideas, and thanks for all your help so far there will be a 17 old kid up for auction pretty soon. just kidding he`s a good kid just couldnt keep his fingers off that carb i think thats where the problem can from.

Are you sure the carb adjustment didn't come after the engine was broke ,to try to get it running again:( ?If you are sure it was just a carb adjustment ,then you could concentrate on the carb.It sounds worse then a carb adjustment though.

When you drain the oil get a magnet or two and slide across the bottom of the pan to pull whatever,if anything,to the drain hole.

well like i said , did u see anything on the plugs? pull the valve covers check inside there first, bent rods? Anything could've happened if he was messing around in there. he could've dropped something down carb. or if he was running it hard he could've over reved it jumped time, cam, dist shaft , threw a valve. Hopefully its something stupid and you'll make him learn how to repair is own toys. good luck and i'd check old oil for metal, might give u a better idea where to start. no metal-top. metal-bottom