The engine is going in a nice 66 fairlane , primarily to blast around on Sundays but will be driven probably most days. Longevity is of course a priority but if it lasts 40k miles with 600 odd hp and 60k with 500hp then I'd go for 600.
I'm new to this and flow charts and cam specs are alien to me. One thing though if the iron heads flow 306 @500 lift can you get 700 lift and if so will they flow a higher figure?
Ean,
I have been following this thread and the only concerns I have are the comments above from your earlier post. First, I think you can get to 600 hp, iron or otherwise, but you'll end up doing it cheaper and easier with modern heads.
The concerns I have are with the 40K miles comment combined with the .700 lift comment. There is an old saying, "fast, reliable or cheap, pick 2"
A big lift cam will work springs hard, in addition, a big lift cam and spinning an engine high will work all the parts hard. Solid rollers, although improved dramatically in the last 10 years, aren't really made for 40-60K applications, heck in the early 2000s Comp said "75 quarter mile passes then rebuild". The good news is that I do not think you need to go there for 650 hp.
40K miles is a lot, I run right around 600 hp level and elected to do it with a lot of head and intake work, but kept the cam mellow enough to make it very streetable. I think I'll get as many miles out of the motor as I choose, but for the displacement of the engine, I am not making as much power as I could to allow drivability. That was my going in choice, match the engine to the use as a street car.
I think some time spent on where you want this engine to perform in terms of RPM and how you will cruise with it (parade and/or coffee cup in hand, or hammering it when you take it out), will allow a real strong engine to emerge. My hunch is that it needs to be less than a solid roller screamer.
I'll add that I think your numbers can be hit with a nice deep breathing stroker, hyd roller (if your block is drilled), and nothing all that fancy for intake or carburetion. Remember, Blair hit mid 500s with a relatively mild pair of 445s, add 50 cubes, more head, and more cam (if it matches your desired end use) and you'd have a very reliable 600+ horse
Your current cam may be usable, but likely it will hold you back. If we can figure out all the specs for it we can advise better, but odds are, if its old, it'd be a compromise.