Is there any advantage to using 68-69 rockers on a 1970 455, and will it even work right? Somewhere I thought I read something about them being stronger than the 70 rockers..... Thanks!
I think the ratio is a bit more on the 400/430 arms too Cole. 1.52 compared to 1.59 as I recall. Dunno.............
Thanks, Dave! I appreciate the response. I also had forgotten that JW had posted a rather in-depth response to a rocker question a few days ago.........must be the lack of sleep! Here it is again: JW said: Welp, couple options here. For the $625, you can get TA's 1312 1.6 rollers, and add $115 for a set of good pushrods. I suggest you stay away from the 1.65 stuff for street use, especially with a hydraulic cam. That's more of a race rocker, with solid/roller cams, and can cause some issues if you have too high a tip height on the valves. I have seen that.. That option is $740.00.. most durable, possibly overkill for most street applications. Nice adjustment deal tho.. Definately getting what you pay for here. I like Steve's approach with the 430 rockers, that's a nice setup, only issue I have ever seen with them is the valve end pad fall out sometimes.. we used to use them on the big race cams back in the day, before we could afford KB rollers, which was "state of the art" at the time. I use this rocker on the Level 1 and 2 iron and Alum motors sometimes, if the budget permits. TA has super nice totally rebuilt units, but make sure you send a good set of assembled 430 cores in, so you can avoid the $125 core charge. But keep the holdown buttons, you will need them for the new ones, as they are not included. If going this route, you must use the hybred adjustable pushrods.. I know.. we used the standard 5/16 ball end rods on our race car back then, and got away with it, but when I tried to do that on a street motor, it mushroomed the end in the rocker.. they were TA's standard adjustables. We changed out the ends to the 3/8 ball ones, which is what you get with the hybred rods, and never had an issue. Took a good 500 miles on the motor or more to see that problem, but it did happen. TA's Rebuilt 430 rockers, PN 1300-430 is what you need, they go for $259..(as long as you supply a core set) Pushrods are TA 1427B's at 149.00.. So you will have $412.27 in that option, and also have an adjustable valvtrain. I would add a TA roller rocker stud kit to the deal, for an extra $27. Next up would be variations on the stamped steel stuff and aluminum stuff. I beleive Mike(TA) has the 70-71 aluminum rocker arms, rebuilt with steel shafts. They list HD shafts, I would assume that means steel ones, instead of the wear plauged aluminum shafts on those motors. And then they have the stock replacement kits, (TA 1317) with new stock shafts and stamped steel rocker arms. Perfectly adaquate for most street motors, I only do one thing to increase durability on those, and it is what I did with Brian's motor. Yes, you can get the roller rocker shafts idividually, but at $90 a pop, that gets a bit spendy, when your trying not to break the bank. If we look at rocker arm failures in general, we will see that what happens in almost all cases, is the stock rocker arm shafts break, right where the bolts go thru, typically on the ends, since that outside exhaust rocker is supported only on one side. To help eliminate this problem and still keep the budget in mind, I sometimes use the TA Roller rocker stud kit, and the hold down buttons for the rollers.. this spreads the load out on the stock shaft, instead of just in the little tiny area that the bolt touches. I don't recall the exact costs for the hold down buttons, as my accounting program is in the computer at work, but if you can lay your hands on a set of 400/430 hold down buttons, they will work, otherwise I would imagine that TA would sell you the holdown buttons for the rollers.. they sold them to me, but I know Sheri does not have a part number for them, since she pulled them out of a set for me. You should call TA and ask. I think they are like $8.00 each, and you need 8. Add a roller rocker stud kit, with the nice washers and nuts to the deal for $27.00 PN TA and your all set. Total cost on that option, would be $230. Cheaper yet if you can get ahold of the stock 430 holdown buttons, which are not everything the roller rocker ones are, but better than just the bolts stuck thru the shafts.. stock shafts, with just the bolts, and a performance cam/valvespring setup, is asking for trouble. I am sure plenty of you are getting away with it, but maybe not forever.. Now, always use the TA 1423 5/16 hardened pushrods.. lots of flex in our over 9 inch long pushrods and Mike offers them in lengths for 9.275 to 9.750, in .050 increments. 9.300-9.500 are the lengths most often used. When building a new motor, I suggest that you get a checking pushrod, dial in your preload, and order the right length. Checking pushrods are available from Jegs and Summit, Comp cams PN 249-7704-1 is the one you need, for like $24... So make sure you add $115 for the pushrods to the last option, for a complete comparision.
