Fritz,
Based on my personal experience here in Brazil, where we have just no option on rubber seals, most of the engines that are supposed to run with a rope rear seal ends up usning them.
It is possible to use the rope, and live dry with it. I have succes many times, but it is a somewhat tricky task. The best rope available was one we could for as long time buy at chevy dealers, it had a very small and thin red hair in the ends. They were supposed to be imported from somewhere and after sometime they just disappeared. These red hair ropes were easier to install and normally did not leak for a long long time. They were supposed to have asbestos. But I also used the regular graphite impregnated rope also having very good results.
We used to have Mopar 318 here in Darts for a long time,all they came with rope from factory. But I use to assemble them using rubber seals and always a good result.
Some tips: 1- always have the retainer groove completely clean and use a rtv bead where they contact the block,
2- always use a small amount of rtv to help seal the rear main cap to the block.
3- don't forget to wet the seal contact surface to the shaft, or you may fry it on the initial start up.
4- do not wet the halves contact point, the place in which the 2 halves go togheter.
Wish You ggod luck in the process, I see many fellows here prefer the rope type, and yesterday night I assembled a 261 for the first time using a rubber type seal that a fellow bolter send me sometime ago and I was saving for a special ocasion. I have always a good time when swapping from rope to rubber. And I have done it on 318 and hope to have the same luck on the 261. No suggestion on the wiper rod also.
squeeze
The best part of working on these low tech engines is that they do offer us great margin to improve them. As I stated before, I love swapping the rope with rubber seals and always got nice results. Got a big service here for a museun of the Brasilian Transport Memory Foundation, and the owner/responsible for the vehicles asked me to improve 2 engines they have on cars that are supposed to go to external activities and oil leaks are always a problem. They use a 261 and the other has an early flathead 60 horses model.
The 261 was real easy, a complete overhaul, a li'l more compression, better cam and headders. The engine was assembled using a rubber seal.
The flathead was machined to accept both front and rear new one piece retainers. This engine has an aluminum oil pan that was welded and then machined to make a adequated saddle for the retainer. A lot of machine work, but the results are in to be worthwhile. And I'm really anxious to have them both running soon! The flathead has an unique ArDun style conversios heads available only in Brazil for a short period of time and it looks really nice and powerfull.
