First off...
You'd be hard pressed to find a bigger "cheerleader" for stock equipment, be it as cast, or modified, than myself.
All I will say about Thumper's product is that my opinion is his customers have not proven them to be performers, and the controversy surrounding the advertised flow capabilities are 2 factors that would be enough to keep me away. My opinion.
Ed H. has gone into the 11's with untouched shortblock, and carefully selected untouched heads intakes. He does run a very sporty cam... more than most would care to live with. Full weight.
Bob C. has gone 11's with ported stock heads/intakes, but with a more friendly/streetable cam. Full weight
A chap out east has ported stock heads, wild cam, and carb setup and is shooting for 10's N/A. 2600lb car. Currently running Low 11's.
So, the "stock" castings will support performance, but, there'll be trade offs in drivability and fuel ecconomy.
A restricted intake/head combo is more dependent on proper camming than aftermarket castings that'll make decent power with just about any cam, on account of the volume of air they'll move... errrr, sort of, but you get the idea.
A tiny 125-145cc port of a stock, or hog'd stock head is going to need as precise a cam grid as aviable to keep up/come close... aka as much help as it can find.
Can the little iron heads be made to run with the stock 6037's and 165's out there... yes... but at the expense of some drivability and most cases, your wallet.
Is a proper cam the secret to doing so? Absolutly.
Are there many folks responding to cam questions on the message boards who are informed and knowledgable? From what I've seen no. And I don't pretend to be an expert, but, know enough about "stock" combo's to know when I see bad advise. Only on account of having researched my own 'stocker' build, and having talked extensivly with proffessionals, with result orientated backgrounds.
I've seen a few custom cams designed for stock, and modified stock castings, and they have favored the exhaust.
The myth is, that E7's need an exhaust bias'd cam, which, I'm not intelligent enough to agru, however, having seen the spec's on cams that have been ground/selected to run "stock" heads hard, I've not seen the exhaust bias. At least not with regard to the typical advertised durations/lift
More fuel...
The B cam (oh boy, here we go) was cooked up to run with stock heads('er, at least I've been lead to believe that).
Narrow seperation, no exhaust bias, and, fuel economy isn't there.
And, I've got a friend running the B, with stock GT40's(flow typical a economic ported E7) running low 12's (12.3's actually) at over 110mph in a full weight LX. Not bad for a crappy outdated cam. Intrestingly, above mentioned worked stock heads advertise more flow, and often spec the B... but find me a car in the low 12's n/a with those heads.
Ha! Then again, not knowing valve events, and abviously not knowing how to interput them correctly, that doesn't carry much weight for B either does it? LOL!
Out of curiosity, what are the valve events of the B and F cams?
So...
These are not necessarily things I know, rather things I've paid attention to, and drawn my own conclusions.
For myself.
I've run into the 12's n/a with stock long block, stock
suspension, and no weigh removal.
My current project is ported stocker E7's (not Thumpers, nor do they flow as well as Thumper advertises) TMoss lower and a custom cam via Buddy Rawls. I hope to go into the 11's with this combo.
Oh, and my custom cam, does not favour the exhaust... FWIW...
Again, things I've witness'd, been explain'd, not things I know.
-flame suit on-