Aluminum vs iron block

I know there's tons of literature out there on this subject, just wondering what some of y'all think. Shopping for a block to build and there's just too many options. Hoping some experience can point me in the right direction.

Iron/aluminum block

Hydraulic/mechanical roller/tappet combo

There's a voice in my conscience saying go iron block with hydraulic roller camshaft but then there's this idiot saying aluminum block with mechanical roller camshaft

Not building this for street, but don't want high maintenance constant valve adjustments etc

I imagine myself driving it on the street sometimes but speed limited to 55-60 mph topspeed and having to pullover and cut the engine if I encounter traffic

Or should I just put this thing on my existing iron block and get some pulleys and call it a day, this is pretty new to me and theres so much to learn and I can't stop thinking about it, trying to learn everything myself and order parts so I can make her pretty and loud just to keep her in the garage to look at and wax on the weekends, I think I had too much coffee this morning lol people ask me what type of use are you going to be using this rig for and I say bunch of romantic fantasy type stuff like towing a bulldozer out of a swamp but in reality I'll probably just drain all the fluids and hang out with her in the garage drinking Budweiser listening to Keith Whitley testing out fancy imported paint glaze and wax products or I'll just sell her to the next sucker and get back on the lake and terrorize some bass

Hey Rusty,

In my opinion stick with the iron block.  Aluminium has so many other factors that have to be considered they are better left to full on race applications. 

I remember when Honda started providing engines for Indy Cars.  They had failures that were not discovered for about a year. Even with all their resources and engineering there had to be a great effort to find a problem.  Turns out the aluminium blocks were distorting just enough to "twist" a bearing saddle and cause oil starvation.  

Now I'm not saying you will have this problem. The point is, an aluminium engine has to have all components engineered to support the design of the block.

You want to have your Bronc for the pleasure of it.  Save yourself headaches and use an iron block. If nothing is wrong with your current block use it with a good set of iron heads, roller hydro cam and have fun.

Good Luck