I know there is some threads on the board here about this, but much of the information is scattered about and hidden. I have a few questions about the install. I know some of the guys here have done it. I have been doing research on putting a later Pontiac motor (post 1959) into an earlier chassis (55-57 Pontiac). I know about fabricating side mounts and a later trans mount. Got that. My questions are about installing an early timing cover on later motors and using the factory style front mount (chin mount). Okay: Please let me know if I have this right: 1960 cover was the first year of "normal" cooling and earlier timing covers are for the "reverse flow" cooling. The 1960 timing cover is not aluminum and has the mounting surfaces necessary - I think. Crank diameter is smaller on the 1960 cover (and earlier) and the best mod is to bore out the crank hole and install a newer seal as stated in this: http://www.pontiacsafari.com/L1Garage/FrontSealUpgrade.pdf ===== Questions: ===== 1. I appears that later covers (later motors) have the same mounting surfaces to use a "chin mount". Are these covers not used because of the material used or in fact do these cover not have the mounting surfaces? 2. If using the 1960 cover on later motor, what must be done with some of the smaller water passages? I would seem there is holes that do not mate up. 3. Is there any block modifications that need to be done? Ie, drill/tap any holes in the block or cover? 4. What year gasket is recommended? Thanks for reading and I hope to get some responses PS: I am asking there same questions on the Pontiac boards also, just in case you read it there.....
NOT MY CAR NOT MY CAR: I found this picture on the internet.... This looks like using a later motor (cover) and simply bolting it to the cross member. Is this wrong? Or at least bad?
My understanding is 1959 is the last block that was made with provisions to use the chin mount on, certain holes drilled and tapped on that block do not exist on later blocks. Which holes? Only way to know would be to try the older cover on the later block. The chin mount cover is iron, the later ones become aluminum at some point. They were iron because the aluminum won't support the motor with all the vibration and stress. You're basically asking to break it at some point, which could get messy. So you're stuck using a 58-back cover to do this swap. I don't know if the 59-60 cover will work - but a Hollander interchange lookup might tell you. Given the early water pump is like $100, the early heads use diffusers, and all the other changes, I don't know why you'd mess around with these things. There also is the fact that when they get old, they just come apart, when I bought a couple of '56 engines in a junkyard years ago, we never unbolted the front, just picked it up and it pulled right out. It's not that hard to make a set of side mounts up.
Okay, what I am trying to understand is; if I wanted to use, say a 1969 400, bolt it into a 1957 chassis. What would be needed to do: Use a 1960 timing cover because of the strength (not sure if the mounting surface differences) and do some work to the cover. Maybe do some drilling and tapping to the block if necessary once I attempt to bolt that up if there are other holes in the cover and not place for a bolt to go. I get the rear (bell housing mount) thing.
Make some side mounts, is what you need to do. I'll say again, the block is missing holes to work with the chin mount, the chin mount is weak and prone to breaking clean in two, the chin mount was made to use with older, less powerful engines, and there is a reason GM went away from it. Then you have to deal with the cooling system differences on a 1960 versus a 1969 motor. I looked at running the late front cover on the 1959-60 engine and I also ran into an issue with the crank snout seal and harmonic balancer - you may be able to scare up a seal that will work because the cranks should be the same diameter, but it's possible the 1969 balancer will need a bunch of games played to make belts line up. When you can make side mounts out of a piece of tubing and a couple pieces of bar stock that will take a factory upper mount in just a few minutes, again I will repeat it's not worth the cost or the hassle to sort out all these issues for a mount you're liable to break anyways.
What would be the cooling system differences between 1960 and 1969? I was also planning on using the older accessories. As far as the balancer I would have to work with that and compare the two.
I would leave all the 69 stuff on the engine unless you like scrounging for obsolete parts. What are you going to do for exhaust? Looking at the picture, you might be able to flip the exhaust manifolds around so the dumps are in the front. You might have to make some engine mounts.
It does not mater who's car it is. If you are trying to put a later engine in the same kind of frame, it will end up being the same. They changed the cooling system more than a few times on Pontiacs. The 69 and later is the last cooling system change. The picture you posted is a Pontiac engine with 75 or later heads, I can't tell what year block it is. A 69 engine with have 3 motor mount holes in the block. Post some pictures of what you are working with.
Okay, what I am trying to understand is: If I wanted to use a 1969 Pontiac 400, bolt it into a 1957 Pontiac chassis. What would be needed to do? I understand about fabricating side mounts and the rear trans mount if I wanted to go that route... What if I were to use a 1960 timing cover? From what I have learned the 1960 is the first year of "normal" coolant flow and the last year of the iron cover that is strong enough for a "chin" mount. I have heard of others do this. I just don't have all the details. I get the rear (bell housing mount) thing. I have a TH400 and I have the capability to fabricate such a mount to make a "mid mount". I could also make up a cross member to use the normal TH400 mount also. I would NOT just do the "chin mount" and the normal TH400 mount. I think that would be too far apart for the mounts. I have a 1969 Pontiac 400 with a TH400. My block has the 3 holes not the later 5 holes that came out in 1970. I can fabricate the mid bell housing mount and even use the other rear mount on the TH400 if wanted. In reference to the picture.... I know I have the same situation. That is why I am asking about the safety of this mount. By looking at the water pump I can tell it is not a 1960 timing cover. I have read elsewhere on this board that the 1960 cover is the one of choice due to the fact that it is stronger material. My other questions concern the differences in water passages. I know the 1960 and the 1969 both have "normal" flow, but is there other issues with bolting them up? I would be performing the crank seal modification.
The engine in the pic is a 65 and up (including timing cover) and the rubber mount you see is just a block holding the engine in the chassis while the guy is building his engine mounts. Side mounts are pretty easy to make and Sanderson is (finally) making a shorty header that will fit all kinds of chassis. Good luck, -Abone.
Okay, by your answer you also think he should have fabricated other mounts. That is what I thought also considering he is using a later timing cover. But I have other pictures that show the completed car with no other mounts. Again, not my car. This was a car that was for sale awhile ago and I looked at it. The seller gave me some pictures of the build. Beautiful car, but I did not have the money for it. This is the completed car... I cannot see any side mounts. I am not criticizing his build. Just want to know if anyone would do it different. When I was looking at it.. I did not know the difference about mounting, year differences, etc. If this is anyone's car here... I hope I am not offending you.
Sure glad our Canadian Pontiacs all had chevy engines and chassis. Makes swapping in a newer engine and tranny a piece of cake.
Hmmm...that is very interesting. The timing cover on that engine is 65 and newer which has no provision for any sort of mount. It does have tabs on each side which were used to clamp the transmission lines. (I THINK they clamped the lines on those tabs, can't swear to it...) The spot where he has the mount is a kind of notched flat spot in the pan right at the timing cover that I always use to balance the front of the engine when building engine mounts. How he is incorporating that timing cover to mount the front of the engine, I have no idea. I wouldn't use the aluminum timing itself cover to mount the engine...maybe if the mount was incorporated into the front few oil pan bolts, maybe... Still, if the engine is mounted only with this front mount and the rubber mount at the rear of the transmission, I wouldn't recommend it. Looks like nice work though... -Abone.
I have looked at the mount again and it sure looks like that is the only point the front of the engine is suported. It would be nice to free up some room on the side of the engine, but I definately would not recommend mounting the front of the engine off the teeny weeny timing cover tabs. Here is a mock up of my '34 mounts. If you give your headers some consideration when you build your mounts, you can usually keep them out of the way. Here is about the only finished shot I have that shows the header. I did have to build my own headers to fit the engine in the chassis, but the mounts were about the only thing that wasn't in the way. Good luck, -Abone.
As long as the block is flat all the way up on the front the 60 cover will work, I had one on my 66 389. Used the 60 gaskets and the block sealed up the unused hole on the cover. Might not do you any good but i'm not using my 60 cover, I can sit it on my extra 67 400 I have. I can't say for sure but the 69 should be flat also. I know it would not seal up on my 74 455 without filling in the cover with a freeze plug. I'm not for sure on the change the way the front of the block is. Than make some side mounts each side of the trans or some kinda midplate.
Thanks, you have confirm my thoughts about the car in the pictures. Is there anything about the use of the vibration dampener interchange if needed?
No problem, I checked my 67 400 block and it's flat all the way up to the valley pan on the driver side of the block. My other 73 455 isn't so somewhere in between is the change.
I made side mounts on a 1957 Pontiac Chieftain with a '67 400. The shape of the frame, headers and steering box make it challenging... Here are a couple of pics.
Very clever. I never would have thought of making a mount that straddles the steering box. Is that 1/4" thick?
i did this on my gmc 1958 using 1967 engine 1960 front cover with same water flow as 1967 engine front mount and stock trans /engine mid mount and a extra trans mount for 700 trans. work was to fit adapter plate and trans/engine mount but on a pickup it is more space.see pictures on my build here on HAMB. ken sweden
Yes, Ken. I read your build. I liked how you made the transmission adapter also your mid mount. Very nice.
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