hotrodpc

1967 425 in 80 GMC
New to the site FINALLY. Sure seems like alot of hoops to jump and waiting to get on board. Just have to tell a story how it came to be that I am interested in Olds now. I had a gf that had 73 Olds Omega with a 350. That was a long time ago. Wish I would have kept it now (the car, not her), and I have worked on a couple in the past, like a 68 Cutlass of my bro. I bought this 80 GMC truck for $200. It used to be diesel but had been converted back to gas using a 77-80 Olds 350. Read up on it, found out about windowed mains. I am not interested in keeping it I don't think. I belong to a truck forum that I did not have to jump through hoops to get online and respond and interact and been there ever since. Told a user about me wanting to change to a Chev 350 that I have sitting in the backyard awaiting a rebuild. He told me to look up the specs on the Olds 350 and I might want to keep it 350, just get a differant 350. So, he is right, the Olds 350 would be better than the Chev 350, but then I decided I may as well just go with any Olds Engine, like maybe even a 455 would be cool. Been keeping an eye out. I came across this motor and trans in a pasture. It was red, and I can tell by the width it was a big block. The trans still bolted to it, obviously a T400 with a tag of 67 OB. So I bought it knowing that the Trans would have the good sprags in it and I would not lose money. It turns out to be a 1967 425. Block ID 389244 D. Heads are 394 548 C. Intake is 4bbl #390390. There is a # of R151850 stamped on the front of the passenger side head. That is supposed to mean something but I don't know what. Can anyone help with that? Also the other cool new about the T400 is is a Variable Pitch trans. Got the 2 prongs on the kickdown, and the short stator with the groove behind it. I am aware of the 39 and 45 degree bank issue. It being red should be the least common 45 degree block. For some reason, by eye ball, it looks to me to be 39 degrees. The pushrod geometry is not straight out of the lifter to the rocker. So if it is 45, then 39 would be even worse on the angle I would think. At any rate, I am sold on this motor and trans, and I will taking out the Olds 350 and T350C and putting a truck threaded short tail shaft in the trans when rebuild it, and have a toggle switch pitch T400 with a 67 425. I am sure it will make a nice sleeper and certainly see some head scratching when the hood opens up. If anyone has info about the 425 I may not know, or any idea what the R151850 is, please feel free to reply and let me know. I guess there is no way to know what this came from originally? I know it has never been cracked open until I cracked it open. Sad to see the weather tooks its toll, but I can revive it. It has been sittiong out in that pasture for over 15 years that the lady knows of. Off topic a bit, I also got a 67 Pontiac 400 w T400 and a 74 Pontiac 400 with a T400.

2blu442

Welcome to the site! I've got a 1979 GMC Short Wide bed with a tired 1970 350 Olds engine in it. I've got a 455 in the garage but haven't had time to put it in. Yes, I like the Olds engines and think a big block in a pickup is a sweet combination. The letter in front of the numbers stamped in the head tells the application. Off the top of my head I don't know what the R was for, since it has a normal transmission it's not from a Toronado so the most likely possibility would be an Olds 98 or 88. Someone who knows full sized better than I may chime in with the exact application. The C heads would be a 1967 but you've already got that down. Post some pictures when you get a chance.

Sorry about the hoops getting on the site. The spam and occassional **** was getting bad, and we like this to be a family friendly site! But you in now so post to your hearts content! John

hotrodpc

Awesome truck. Yeah get that 455 in it. I was telling a few people about this 425 going into a truck and a few said Oh No No No, that motor is to good for a truck. Find an Olds body. Well if they were cheap enough I would. I may end up liking this motor enough, it ends up in a differenet better truck. I only got this idea because this 80 GMC is already set up for Olds with the wiring harness for starter, etc on the correct side, the mounts already in it, and trans too, but I think I want to play with the Variable Pitch 400, so its likely going in it too. I just hope I can save the motor. It has sat out in the weather for at least 15 years. Sad !!! It had never been craked open before until I took it apart to see the damage. Its seized of course.

joe_padavano

Welcome. By the way, paragraphs are your friend
(or at least the READER'S friend!)