Are the valve springs form a 1976 455 Olds the same size as a 350 - 403? I got a junkyard 455 to toss into my 442 just to get it back on the road cheap. Picked up a barely used Isky cam and lifters to give it the right sound. .470 lift at 280 advertised duration. I plan to use all the stock valvetrain, exept a new roller chain and new springs. I found these springs http://store.summitracing.com/partd...rt=EDL-5812&N=700+4294925232+115&autoview=sku but they don't say 455 in the application spec. Does anyone know if I can use them? Thanks, Joel:TU:
Olds was really good about interchangeable parts. You could actually swap heads from BB to SB, or vice-versa. One difference was the headbolt size though. I'm fairly certain that they both had the same installed height. Been a few years since I setup the springs on a 455.
Joel: I'm no engine builder, but do know a few things about them. 1. With regard to valve springs, there were quite a few different ones used. Anything good has an internal damper spring that is more like a coiled ribbon than just a smaller major diameter coil that fits inside the larger outer one. 1968 W31's used a special Swedish steel aftermarket spring that came in on the heads when they were received from the outside vendor that did those heads on the first 500 68 Ramrods. I'm not sure how they handled it on the 69 and 70 W31's as those heads were machined and aassembled in the Olds engine plant. I'm sure they were something to handle the higher RPM's that those engines run. 2. Olds had deep and shallow spring pockets. Prior to the 1970's, they used conventional retainers and had shallow seats. They started using valve rotators on the #6 and G heads in 1970 (I believe only on the exhaust valves) and those heads had a mix of shallow intakes, and deeper exhaust spring seats. Castings were the same, just a little deeper machining. In 1971, they went to low compression and unleaded fuel very late in the program and didn't have time to do something about the rapid wear on the exhaust seats caused by the reduction (and later absence) of the lead in the fuel. The rotators greatly reduced valve sealing life. So they went back to standard retainers on the exhaust valves, too. I don't think they had time to retool the seat cutting machines, so my GUESS is they used a different height spring to compensate for the difference in compressed height caused by the change back to the retainers. These heads in 1971 were #7 on small blocks and G code on the big blocks. In 1972 they resolved the wear problem on the exhaust valves and used a flame hardening process on the exhaust valve seats and returned to the rotators. The casting codes on these heads were same as the 1971 heads (#7 and G) but had a smaller "A" suffix after them to denote the hardened seats. Still with me? Bottom line is there were valve spring differences all over the place back then as they scrambled to accommodate the lower lead fuel virtually overnight. Compounded by the fact that Olds engineering had pulled their best engineers off the performance engines (W cars and experimental stuff) and put them on emissions research and development. So.......using one set of springs on another set of heads is a shot in the dark unless you measure the force at open and closed heights that match your camshaft. Same as you would on a serious performance engine. UNless you have a lot of time on your hands, that's probably more expensive than just buying a set of new Comp Cams or other performance springs at Summit. Sorry about the epistle, I usually only do that on the ROP Olds site, but that's not too friendly waters these days. Besides there are lots of very good performance engine builders that can do a better job explaining this than I, Too bad all they do is throw all the stock parts away when they do an engine and replace with aftermarket and charge you $8k-$12k. Each seems to think he's the only person on the earth that knows how to do it....right.
Scott's right,they'll all fit, but to get the max, you have to have the right length valves and the valve job has to put them at the correct height if you're going to use the stock (non adjustable) rocker design. Swapping big block and small block heads either way woill bolt up, but the port heights are radically different at the intake and wouldn't run that well. But it will fit and run! :laugh:Olds small and big blocks are virtually identical in exterior dims and component placement from the water pump on down. Unlike Pontiac, the big blocks have about an extra inch in deck height for the much larger stroke for the big block. That dictates a much wider intake with different port heights. Also dictates that you can't interchange exhaust manifolds from the good ones(relatively speaking) on the big blocks to this firewood shapes we have to run on the small blocks. So why don't you just buy this 67 numbers match E block that runs 11's and sounds stock? I originally bought it for my 66 to run FAST, but I'd have to use B heads instead of the correct C's on the 67 engine. I'm practically giving it away and could probably part it out for more than what I'm asking for it. But I'm not into that, there's more to this than just the $$$. Now there's an understatement. :laugh: :laugh:
this site will set you you up with the proper springs you need :idea2: http://www.supercarsunlimited.com/Items.cfm?CategoryID=121 also here some more info on olds valve springs http://www.supercarsunlimited.com/info/tech/techindex.htm
Thanks, Mark. GReat post. Greg does an excellent job explaining this and I never knew those tech pages were there. Class outfit. :beers2:
