[jabooth]

In mid '05 I bought my first Cobra, a Pilgrim with what now seems a bog standard ex-1978 SD1 3.5V8. With K&Ns on the SUs, and 4" sidepipes, it wouldn't run cleanly above 3,000rpm under power, and previous owners over the 10 years of its life have obviously accepted this! Thanks to all you knowledgable Cobra nuts on this site, I confirmed my diagnosis of "wrong needles" (they were the standard SD1 BAF needles), and shelled out the massive sum of £20 to almost solve the problem with BCAs. It's still a bit lean above 5,000 on full throttle, and it smells a bit rich at lower speeds, but at least it goes!
I'm considering ditching the SUs in favour of a 500cfm 4 barrel (Weber/Edelbrock) on Edelbrock manifold plus a fast road cam to give it a bit more "zip". You see these advertised for £500+ and £250+, but how much power uplift can I expect for these changes (155bhp was the quoted output for the SD1, which should be a little more without the strangled intakes and exhausts)? Can these prices be significantly beaten, and where's the best place to look? Also, the ignition seems to be working OK, so is it worth the expense of dual point, or even electronic distributor replacement? I'm not looking for a racing engine, I'd be happy with up to 250bhp and no more than 6,000rpm. How near can I get to this without spending a fortune? If I wanted more, I'd go for a Yank small block transplant, but I really don't want the hassle, I'd rather drive it than build it!
Any advice will be much appreciated!

Tony