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terryggoround · 08-24-2014, 12:09 PM

I have a 1970 GMC JIMMY and my engine threw a rod the first time I took it out after a frame and axle shop had it for 2 months(had the front and rear end rebuild also all the body mounts and bushings replaced). The shop was supposed to balance the drive line and replace all the u-joints but was not done as I was 60 miles from home when the drive line came off the yoke at the transfer case. When my husband and I used some bailing wire to tie up the driveline and then he got in to put the truck in 4high only to find out it was already in 4high(the wrong boot is on the shifter and it covers the whole shifting plate). I thought when i picked up the jimmy from the shop that it seemed like the clutch was a little more torquey the normal but i thought it was just because i had not driven it in 2 months. After getting the jimmy back to camp i took my husbands 85 jimmy and the driveline home and back to the frame shop. The owner who was the one who worked on my Jimmy was not there but the shop took the driveline and said they would have it ready in 2-3 hours. This was a friday and I was very angry that I was not able to talk to the owner as he was out on service calls the whole day but the shop called me in 3 hours and i was on my way back with the balaced driveline with new u-joints. The shop also did not charge me a dime. That told me that my driveline was not balance and the u-joints were not changed when the rear end was being worked on. To make a long story shorter I got back with the driveline got it back in my jimmy put it back in 2h and took for a test drive. The jimmy ran fine or it seemed so. Later that night I was getting ready to come home checked all the fluids ect everything was fine. On my way home(30 miles to go) the truck starts loosing power and what sounds like loud static coming from truck then i hear and feel a loud bang and black smoke is pouring out of the engine compartment. The flatbed tow truck driver said that I might have blown an oil line cause there was alot of oil all over the ground behind my truck. I was sure in my mind that it was more than that.so after getting home and the jimmy unloaded I grab my flashlight and had a look. what i found was one hole (about the size of a 1/2 dollar)on each side of the oil pan with one of the parts that hold the piston to the crankshaft sticking out. I only bought the jimmy in January of this year and had only put about 150 miles on it after getting it home from Fresno(where I bought it) I had been told the motor had been rebuilt and had only about a thousand miles since.
Now i have been looking for a motor a crate or rebuilt. Have been told that a crate motors with EFI are about $1500 to 2500.00. But I want the same motor it came with that has a carb not EFI. The motor it came with is a 350 v8 5.7l with a 4 speed manual transmission. The transfer case is a Np 205. I have talked with a few online engine rebuilders and have been told they don t have anything in stock.
Any suggestions? I want my jimmy running again and soon before the rain starts. The one place that had a crate motor in my budget was Sims racing but that engine has EFI.
Thanks for your help from a fairly new 70 Jimmy owner!!

08-24-2014, 12:09 PM	#1
terryggoround Registered User Join Date: Nov 2013 Location: Oakland, CA Posts: 34	1970 GMC Jimmy engine replacement I have a 1970 GMC JIMMY and my engine threw a rod the first time I took it out after a frame and axle shop had it for 2 months(had the front and rear end rebuild also all the body mounts and bushings replaced). The shop was supposed to balance the drive line and replace all the u-joints but was not done as I was 60 miles from home when the drive line came off the yoke at the transfer case. When my husband and I used some bailing wire to tie up the driveline and then he got in to put the truck in 4high only to find out it was already in 4high(the wrong boot is on the shifter and it covers the whole shifting plate). I thought when i picked up the jimmy from the shop that it seemed like the clutch was a little more torquey the normal but i thought it was just because i had not driven it in 2 months. After getting the jimmy back to camp i took my husbands 85 jimmy and the driveline home and back to the frame shop. The owner who was the one who worked on my Jimmy was not there but the shop took the driveline and said they would have it ready in 2-3 hours. This was a friday and I was very angry that I was not able to talk to the owner as he was out on service calls the whole day but the shop called me in 3 hours and i was on my way back with the balaced driveline with new u-joints. The shop also did not charge me a dime. That told me that my driveline was not balance and the u-joints were not changed when the rear end was being worked on. To make a long story shorter I got back with the driveline got it back in my jimmy put it back in 2h and took for a test drive. The jimmy ran fine or it seemed so. Later that night I was getting ready to come home checked all the fluids ect everything was fine. On my way home(30 miles to go) the truck starts loosing power and what sounds like loud static coming from truck then i hear and feel a loud bang and black smoke is pouring out of the engine compartment. The flatbed tow truck driver said that I might have blown an oil line cause there was alot of oil all over the ground behind my truck. I was sure in my mind that it was more than that.so after getting home and the jimmy unloaded I grab my flashlight and had a look. what i found was one hole (about the size of a 1/2 dollar)on each side of the oil pan with one of the parts that hold the piston to the crankshaft sticking out. I only bought the jimmy in January of this year and had only put about 150 miles on it after getting it home from Fresno(where I bought it) I had been told the motor had been rebuilt and had only about a thousand miles since. Now i have been looking for a motor a crate or rebuilt. Have been told that a crate motors with EFI are about $1500 to 2500.00. But I want the same motor it came with that has a carb not EFI. The motor it came with is a 350 v8 5.7l with a 4 speed manual transmission. The transfer case is a Np 205. I have talked with a few online engine rebuilders and have been told they don t have anything in stock. Any suggestions? I want my jimmy running again and soon before the rain starts. The one place that had a crate motor in my budget was Sims racing but that engine has EFI. Thanks for your help from a fairly new 70 Jimmy owner!!