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I don’t know of any difference in timing sets between any Olds second generation engines. There shouldn’t be anything different on those years than all of the others.
I don’t know of any difference in timing sets between any Olds second generation engines. There shouldn’t be anything different on those years than all of the others.
My thinking also but Melling ,Cloyes ,Sealed power, ETC all list it under a different part number, They also list the late 70's 350 with this different part number. While others like comp, edelbrock or any of the performance lines go not segregate the later 455 or any 350-455 at all
I can't speak to what the aftermarket does. I can tell you that the factory parts book shows exactly the same part numbers for crank gear, cam gear, and timing chain for model years 1964-1975 (and probably beyond, but this particular parts book only goes to 1975). The only difference is that the parts book also lists a HD chain for the BBOs.
Interesting. I just looked in the SA Gear catalog and they do indeed show a different timing set for 75-76. All three pieces are different numbers from the earlier engines. I'll have to look closer at the shop in the AM. There must be something different.
As i stated above Sealed Power and Melling are two more that also list them differently. Sealed Power KT3-498SA3 is 75-76 455/350/307, While KT3-494SA5 is 74 down ALL engines, Melling 3-498SC is 75-76 while the 3494SD is 74 Down all engines, Cloyes also is the same i just don't have their numbers in front of me.
While others like Comp Cams Edelbrock and just about any aftermarket performance set list the one part number from 65-88 all V8's
Was there a difference if the length of the key in the crank on those years? I am wondering if they are making two different crank gears for some reason.
It is very hard to tell for sure by the pictures but it almost look like the timing dot on the cam sprocket is in a slightly different position on the one set. Ill see what I can find out later on.
Its funny how they break them down. These are Cloyes numbers
Set # 1 C3006K 260 75-82, 307 80-90, 330 64-67, 350 68-80, 403 77-79 and 455 75-76
Set # 2 C3082 400 65-74, 425 65-67 and 455 68-74
Those are the Cloyes numbers and break downs i also have
Curiosity , I decided to get right to it. I ordered one of each of the Mellings units( Cheap enough), To actually compare them side by side.
I will be curious to see what you find. I was going to order two myself and take a look. I already have the cover bolted on the 425 I am doing so I cant look at that one.
Why to people take aftermarket application listings at face value? They are proven wrong time and again. One more time: the FACTORY parts book shows the same P/N timing parts for all 1964-1975 Olds motors (and it stops at 1975 only because that was the last year that particular parts book covers). Same thing with the front cover - it's the SAME factory part number for all 1964-1990 Olds V8s. I'll once again point out that one very well respected Olds repro vendor can't even get motor mount application years listed correctly. We've devoted WAAAAY more time to this topic than it deserves.
Why to people take aftermarket application listings at face value? They are proven wrong time and again. One more time: the FACTORY parts book shows the same P/N timing parts for all 1964-1975 Olds motors (and it stops at 1975 only because that was the last year that particular parts book covers). Same thing with the front cover - it's the SAME factory part number for all 1964-1990 Olds V8s. I'll once again point out that one very well respected Olds repro vendor can't even get motor mount application years listed correctly. We've devoted WAAAAY more time to this topic than it deserves.
Joe,
What part numbers does your book show ? My 85 parts book is at home and I will look at it when I get home but the Cloyes catalog shows the oem numbers also and they are different for 75-76. Those numbers are chain 12360440, cam sprocket 381263, and crank sprocket 382880.
The earlier year numbers are 559446, 388049 and 388057 respectively.
I never take anything at face value but if I am working on a 76 455 I am going to order the part number that is shown for that year. Not much choice when the factory parts are probably not even available.
Yes, they are all the same "but" some have said during degree-ing a camshaft that some china made are off. I personally haven't found this to be true yet. When in doubt, Bill Travato, BTRacing, sells a proven set at reasonable price. I would think if there's a timing problem, it'd be in the timing set. Jmo
They might just be superceded numbers but they are different. Now I am going to have to order both sets and check myself to see.
Bill, the 1975 printing of the parts book shows 382800 and 381263 for the gears. Note that Olds part numbers were assigned chronologically. 380xxx, 381xxx, and 382xxx part numbers all date to the 1964-65 model years. Also note that the 1975 400 shown in your parts book is a Pontiac-sourced motor, thus the different gear number. Olds showed a "HD chain" for some of the BBO applications, and a different crank gear but the same cam gear in those applications.
Bill, the 1975 printing of the parts book shows 382800 and 381263 for the gears.
I am really curious to see if there is a difference. I ordered one of each set and will have them Thursday. I just cant imagine the manufacturers making two different set part numbers if the parts are indeed all the same. Ideally we could find some oem GM parts to compare but that wont happen. I do still have the original timing parts from my Wifes 84 307 so that will be one thing I can look at. They "should" be the same as the 75-76 455
I know Ford played around with timing sets in the early - mid 70's when emissions was getting important. They had three or four different variations with slightly different cam timing for the small blocks yet all of the performance companies used one part number. May be something similar going on here.
I got both timing sets. The only difference I see is that the T3082 set has a chain and sprockets that are almost 1/8" wider than the T3006. The thickness at the center hub of the sprockets is all the same. The actual camshaft timing also appears to be the same.
So basically it looks like the T3082 is a lot heavier duty set. Wider chain and sprockets.
I don't know if the original poster has the stock GM set to measure ? The 307 in my Wife's Riviera definitely had the thinner chain.
I got both timing sets. The only difference I see is that the T3082 set has a chain and sprockets that are almost 1/8" wider than the T3006. The thickness at the center hub of the sprockets is all the same. The actual camshaft timing also appears to be the same.
So basically it looks like the T3082 is a lot heavier duty set. Wider chain and sprockets.
I don't know if the original poster has the stock GM set to measure ? The 307 in my Wife's Riviera definitely had the thinner chain.
Yeah, that's what I found in the factory parts book (see post #12). There are two versions of the chain and matching sprockets, normal and HD. The HD applications were only on the BBOs through about 1974. The two chains are otherwise interchangeable.
Bill, Yes i found the same differences in the two Melling units as you found in your Cloyes example, I do have the factory BB one still and the gear dimensions match the thicker/heavier unit, however the chain on the Early OEM unit is even slightly Taller/thicker than the heavier replacement. This difference is really marginal i contemplated not even mentioning the slight difference. So, We now know there is a difference, We just don't know why the change in 75-76
I do have the factory BB one still and the gear dimensions match the thicker/heavier unit, however the chain on the Early OEM unit is even slightly Taller/thicker than the heavier replacement.
