Being as this is your first Cobra one of two things will happen in time.
1. You will learn more about the cars, compare that to the car you have and determine that you would like something more authentic.
2. You will be mostly happy with what you got, for the money, and accept it, even though it's not really what you want as time goes by.
Myself, I started with a long wheel base Cobra with a typical 302 Ford, T5 trans and live rear axle at a good price. As time went on I began to wonder what it is was really like "back in the day"? Could I afford to get into another Cobra that was a little more authentic, closer to like it was in the 60's? I wanted to feel, and live that experience as much as reasonably possible given my budget.
Phase two:
I HAD to have a genuine FE for starters. I HAD to have IRS as well, while some live axle cars are OK, mine rode like a truck. Terribly uncomfortable on the street, but did surprisingly well on the track. Lack of power bothered me, the small block, near stock, just wasn't enough (in time). At first, I thought it was plenty.
So, I found a good used ERA at a price I could afford, while not perfect to original details in all aspects (very few of these cars are) it's "close enough". A genuine 427 side oiler, with original heads and a flat tappet cam. Of course the IRS and a body shape (very important to me) that is considered one of the most accurate shapes around. The whole thing cost me considerably more than I ever thought I would pay for a replica Cobra. But you see, you either get bitten hard by the snake and gotta have it, or your happy with what you do have and don't worry about it.
Only time will tell which way it goes for you...
Many say, correctly, a replica Cobra is little more than a "hot rod". Modded up with modern parts, etc. etc. The logic is hard to escape. good price, good quality and all that. But for me, it lacks "soul". Take the BDR for instance, nice ride, nice price, to much BMW in the mix for my taste, that would always bother me. As you mentioned the SPF, small block or 385 series big block is a typical choice. A nice 351W stroked and bored or a 429/460 big block. Neither appeals to me. An SPF with a "real" FE? Even a 390? Well now were talking, I might bite, at the right price.
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