Like a dummy I didn't take any pictures of the bottom of my engine with the oil pan bolted on so now I hope someone can let me know what position the two pan studs go. I bought a set of bolts from Totally Stainless and when the intake bolts stretched, I decided to just use my original bolts for everything aside from the exhaust manifolds. Problem is I noticed there's two studs with the oil pan bolts and I have no idea where these went. My guess is at the back of the engine but hope someone can let me know. I do not see the position of these in the assembly manual so hopefully someone can confirm this. THANK YOU!
Hi jbeary, My memory says there are no "stud" type fasteners used for the '67-'76 big block Buick, 400/430/455 oil pan. The oil pan bolts go from the rear all the way to the front into the timing cover. Devon
Occasionally you'll run into the two studs,..they are found at the two first holes in the block rail from the front
Typical. MOST (not all) stainless steel bolts are weakass junk. About the same strength as SAE "Grade 2". Unsuitable for automotive use, especially when combined with anti-seize to prevent galling--which then leads to severe over-torquing. Wisdom. What are you using for the exhaust manifolds? Hopefully, not the weakass stainless bolts. At least spring for some decent stainless bolts, or typical Grade 5 bolts with anti-seize and suitably reduced torque. I generally knock ~20% off the published torque spec when using anti-seize. Official Permatex figures are 10 percent and greater, depending on which flavor of anti-seize you're using. I'm too lazy to look up the specific figures for each variety of anti-seize they make.
\ THANKS for the info!!! Yeah, I had thought that the stainless was the way to go with the manifolds because the last time I used grade 8 bolts and almost every exhaust port had to be tapped and helicoiled... Will contact Todd for the correct bolts. I have a few other things on my list for him. Thanks again!
Stud location mystery continues as I am still trying to figure out if these studs are in the right place. If they do go with the oil pan bolts, could anyone share a picture of these in the correct position? Also, since apparently these are uncommon in the pan, below is a comparison pic of my original pan bolts with the new OEM bolts that Todd sent. None of my engine bolts are marked with an "M" which is confusing me. I understand that the original bolts were sourced from different vendors however I'm 99.9% sure these studs came from my oil pan since I separated and bagged bolts together. I just didn't take any pictures of the bottom of my engine before I took the pan off. The stud on the intake seems to be the same (I didn't take it out to compare but I'd guess it needs to be longer) so I thought possibly these studs are accessory bolts that were mixed up and came from elsewhere but ended up in the pan 30 something years ago when the engine was last apart. I know there should be a stud like this in the passenger side head for (I think) the A/C bracket. Problem is I pulled all the A/C stuff off in the 80's which was the last time I rebuilt this engine so I doubt that one of these studs was still there a few years ago when I took the engine apart, yet I also do not have a picture the accessory bracket before I removed that stuff. I put the accessory head bolts in separate bags too (right, left, front, rear etc...). Known pan bolt and stud bolt washers are the same thickness but stud bolts are slightly longer. Oil pan bolts are the only the only engine bolts marked with this cursive "f". Washer on the new bolts is thinner but new and old bolts are nearly identical as they have exactly the same thread count. The majority of my smaller engine bolts are marked "RSC". The bolt at the top is for the bracket (clip) that holds the power brake vacuum line. As you can see, it is marked differently from the bolt right beneath. Both bolts are the identical in size/length and both go in the rear drivers side head. Passenger side rear head accessory bolts are completely different. The bottom bolt is from the crank pulley. so my accessory bolts seem to have different markings. Head and intake bolts are marked with lines denoting strength and no other marks indicating manufacturing. Only "strange" bolts are from the heat stove. Todd was nice enough to send me some replacement bolts since I had only one original heat stove bolt. However the new 455 bolts are vastly different. Any help to identify where these stud bolts go would be very appreciated. I have tried to get info from both the service and assembly manuals but wasn't able to find any on this stuff. THANKS!!!!
My 430, on my Wildcat, has a stud on the passenger side, front. I think it’s the first bolt that installs into on the block vs the front cover.
THANK YOU!!! Looks like I just found a picture confirming this location on my 400 as well. May very well be only one stud since I can only see the first stud (where you described) after I had removed the timing cover in the picture that I'm looking at. Now what the heck was this used for??? I'm still looking for this info in the assembly manual... Can't find anything. Starting to think my car is strange since its numbers matching but does not match any recent pics of GS 400's from '68 I've seen on line. Pretty sure I've been the only person doing major work on this car
I had a 67 0r 68 430 Riviera GS motor. It had a positive Battery cable that had some plactic block that wrapped around the bottom of the oil pan and routed the cable to the opposite side of the block. I believe those studs were used for mounting it. It also had the block for the wire on the starter side like the GS had.
Hmm I don’t see that. Not in the right spot. I wondered if it was for the wiring down to the starter? I’m not sure. Maybe it was for something optional?
@Buicksky @1973gs @bostoncat68 I have some other weirdness going on with my car that I need to start another post to further discuss. They made more GS 400's in '68 than any other year (the most automatics anyway) and my guess is the new body style also spawned some one off "features". Just a bit of engine dress I think. Looks like the transmission lines have their own clip so this must have been a plastic block that's long gone. Would have held the battery and solenoid wires since there's nothing on the frame that does the same function. One thing for sure, the 4 front cover bolts went missing sometime in the past but the rest are original to the car.
I'm not sure on a 68, but all of my cars from 73 through 94, all different divisions of GM, have a stud on the right side near the front of the oil pan that holds a metal clip that secures the trans cooler lines to the engine. Some also have clips that secure wiring. I'm assuming that you are trying to make it original, so you may have to wait until someone posts a correct picture. If you aren't going original, after the engine is back in, just see what runs in that area and place the studs in that location.
Here are some pictures , again I was told and believe this was a 68 GS Riviera 430 motor maybe the Riviera owners can confirm that the battery was placed on driver’s side of the car. One of the mentioned bolts is still mounted here. Don’t know if this was the case in 69 .
I will have to study on this topic soon. I've got a 68 Wildcat to look at. I have not seen any on the A bodies but they have all been ABO (apart by others)
@Buicksky This is perfect! Thank you for sharing. I will need to dig around to see if this plastic battery cable piece is in any of my junk boxes. This accessory may be a weird transitional year(s) thing since they phased out the 430's in 1968. Actually my intake and heads have the same (big port) casting numbers that were used in the 430's as well. What I don't fully understand about the two engines is that the 400 and the 430 are distinctly different castings but they were designed to use the same parts as my service manual indicates, so why even have different displacements? This question is probably for another thread but does anyone know why Buick didn't stick with the 430 in the 67 thru 69 cars? I mean, seeing as they went straight to the 455 in 1970, wouldn't the 430 just make sense as their "high performance" engine for the 67-69 years?
GM didn't allow over-400 CID in intermediate cars in the '60s. An exception was made for the Buick 401; but it was labeled as a 400 in those vehicles. Starting for the '70 model year, the limit for intermediate cars was 10 pounds per horsepower, without the displacement limit.
