Well, the Hyd. rollers should not be high maintaince.
LJS30, the "LA" S/B engines were roller for a very short time. Only a couple of years and not massivly produced. Also, mostly in a 318 size, but the 360 also did come as a roller motor. These were stopped when the change of head design went to the Magnum style. Basicly, the Magnum engine is a slight mod. of the "LA" and that lasted only a few years. There just starting to become cheap enuff to get from a wrecker.
Most guys shy away from paying 3 times the money for a cam than they noramlly would. Also, like BJR was saying, the Hyd. cams can be had with a very steep ramp. The secrect is the .904 lifter. It can handle a ramp nearly as steep and quick as a roller. Key word, nearly.
When the cams reach a track only useage level, like a race only cam, not just a really big whooping street/strip[ cam, but a race cam, the roller has the advantage of course, but not even then there not normally used even when chasing the money. It isn't a mandatory change/mod to do.
Theres also more to making use of a roller than just slipping it in like a 5.0 engine. It is an involved issue for not really much more power. The old Mopar books have the mods spelled out. Drill and the peen the oil passage way and the peen is used down the lifter bore to clearance the tube thats inserted in the oil passage you drilled. Bushing lifters are a mods also sometimes done. To correct angle and safe guard the lifters and oil pressure in case of failure.
It's alot of work.
Just until recent, the cam companys came out with retro fits. I think there 20 years late on this issue and will have to understand that they'll probably not turn a profit on something this late in the game no matter how much they think there the cats meow.
The nice thing about the Fords and there stangs is they come equiped with many things we just simply do not have and pay alot for.
Excellent for the time and allways getting better fuel injection and ignition thats computer controled and good aftermarket support on mods. 5 spd tranny, roller cam in a car called a "Sports car" were the MoPar camp doesn't have a V-8 sports car. Oh wait, we don't have one since what????????' 1974 when the Cuda and Challenger went away?
Sorry guys, the later 4 bangers just don't cut it. While not bad at all for what they are, they are what they are. Sport cars on a everyday passenger car platform. OR, just not up to task.