325 potential for autograss

[park_monkey]

Hello all
Not been on here for a while but I have a question on tuning a 325 engine if you don't mind.
I am looking at engine options for a class 3 autograss car and was hoping for some advice on how much power can be gained from a 325.
The cars are front engined rear wheel drive with multi-valve engines up to 2 litre or unlimited cc with 2 valves per cylinder. The cars are mainly space framed with a shell bolted over the top and a lot of people use the starlets.
Most engines are vauxhall red top but these are mega expensive and hard to come by so I have been looking at other cheaper options for now.
So how much power can be had from a 325 engine without forced induction and how cheaply can it be done?
Speaking to some of the other class 3 lads the main problem will be the size and weight as the idea is to get the engine and box as far back as possible so the weight is at the rear making the car gate better.
Is there a smaller box available that will fit and be strong enough to cope with the power?
Another option that was suggested is to use a newer 1.8 16v engine but that is a bit pointless as there are much more suitable engines for around the same money.
Anyway, any help greatly appreciated, I apologise if this subject has been covered before but I did search and couldn't find anything.
Cheers

[kimbo]

Honestly cant see any future in it for you.
M20B25 with 'bolt on' mods, i.e. cam, big bore throttle body, remap would probably give 190bhp max.
Get more radical and I reckon you can get up to 275 bhp (at least thats what we're aiming at), but at vast expense (I reckon £4 - 5000) if you're starting from scratch.

If you can't (or wont) afford a red top, I'd go for a Zetec or better still a Duratec, pair of cams, forged pistons / rods and throttle bodies and you've got a reliable 240 - 250 hp for half the cost and all 'off the shelf' bits.
Or even a Honda S2000 motor - I think they make around 200hp 'out of the box'.
And don't lets even start talking about the weight of the M20!!
Kim

[park_monkey]

That's kind of what I thought to be honest. I read through the m20 development thread after I started this thread. Thanks for posting, I think it's a no-goer.