I was referring to the h tuff. Had I meant the I beams I'd have said so but I wasn't clear enough as Im typing on my iphone and I hate that so I take short cuts .
I certainly know the difference between the three types of Manley's.

The H tuff are a significantly better rod than the run of the mill manley H Beam. I stand by my recommendations. I've built enough of these engines to know what's upto the job and what isn't. For reference I've seen the normal manleys snap at circa 480bhp. I'm going round in circles here but the h tuff in it's place would have stood more chance of saving the rest of the engine. Which is the point im trying to get across.

Id rather use the H-Tuff over the normal ones even in a build running close to stock as they give extra piece of mind. I know that had I had a normal Manley in my engine the whole lot would have been scrap. Thankfully I had a Cosworth H beam (that are made by Carillo btw) and it was the difference between a failure that can be fixed and a full on engine grenade