Help With Motor Issue...

[Bishops Trucks]

Hey Grinch,
I'm sorry for sounding short. We can help this guy out together. I should be the one called GRINCH today. I'm just in a mood as this is the first Christmas in 7 years my family and I are spending away from my mom who misses her Grandchildren more than anything. Happy Holidays Buddy.

[grinch4om]

Austria? Good Lord! I understand, I have been away from my home in Maine since 1978. This is the first Christmas I will not be with my grandchildren in Illinois but God is good and he is with me and you! I pray for them all the time. And I'll say one for you and your Mom. Peace bro

[Bishops Trucks]

Thank's, and I'll do the same for you.

[HotRod73]

took all plugs out and put the compression tester in 6 and it sounded like i could hear air coming form somewhere like woosh woosh woosh as motor turned over.... only that cylinder really does it 4 may too i dont know...

[grinch4om]

refer to post #44, determine where air is escaping.

[AesC10s]

Like said many times, im sure you have a blown head gasket. sounds like you have a blown head gasket between 4 and 6. id just pull the head and check it out.

[79Silv4x4]

I'm no help but I've never seen a thread where the OP replies to his reply so many times in a row. Get a new motor is my thought

[j hannah]

Hey, Hot Rod, I have a 74 gmc 3/4 ton, 350. 53,000 origional miles. Ive had alot of chevys through the years. I think these guys are right on with the head gasket. especially if its never been apart before. the factory head gaskets are tin,they tend to blow out between the cyls. I would pull the heads,have them magnafluxed(checked for cracks),and rebuilt. While the heads are off, look at the pistons and cyl.walls,especially 4,and 6. if they arent scored,install the rebuilt heads and you should be good to go. where are you in okla., Im at schulter, about 50 MI south of tulsa.

[HotRod73]

im in norman...you got any parts or trucks for sale????

[kenm78]

Just like (grinch4om) said do a cylinder leakage test... bring your number 4 or 6 up to TDC on the compression stroke remove both #4 and #6 spark plugs add 90-100 PSI through your spark plug hole on cylinder you chose and listen if air escapes through the carburator its a bad intake valve, thourgh the exhuast bad exhuast valve, though the oil fill or pvc bad rings, or if air escapes from sister cylinder you deffently know its the small portion of head gasket between the two that has gone bad. Good luck and I hope you don't spend a arm and leg on repairs.. Merry XMAS

[84slopwaggin]

I've often heard that when you install rebuilt heads on a blocks that has alot of miles it often leads to increased oil use, blow by, etc. My opinion just replace the head gasket until you can get a overhaul done.

[HotRod73]

well i started it... went out and did what i could, i almost got the intake off 4 more bolts left then i will pull head and see whats hidden underneath

[HotRod73]

INTERESTING... i was able to read the castings on the block easily... 3970014... it says 70-76 350 with a 2 or 4 bolt main, i asked the guy i got it from and he said its from another truck and it is a 4 bolt main... is that good?

[AesC10s]

4 Bolt mains are very good. good block to built a high horse motor out of. Very strong block.

[HotRod73]

AwEsOmE!!! It say's 70-76 my truck is a 78 and it has H.E.I.... When did this come out? I want to know the year but its not that bigga deal... If i order 78 chevy c10 parts for a 350 would they still fit even though mine is a 70-76 motor??? by the vin it says came with a 305... also its a bonanza what is that???

[HotRod73]

intake is off, i am starting to think that when its time to REASSEMBLE its going to be a hassle and hard to do... is it???

[magnethead]

if you clean the mating surfaces, it shouldn't be too hard


IF you have a boat anchor intake, disregard that statement and get a hoist/a-frame/crane....