Unfortunately, I felt that the poor exhaust system I had, which had been adequate for the 3.5 engine, was restricting this larger engine. I had at this point persuaded Sarge to build his own Cobra replica and he was part way through an AK build and needed some exhausts for his so we combined forces, and cash, and bought a bulk load of bends and straights and I made two full exhaust systems, one for his Chevy powered AK and one for my RV8 Sumo. What a pain making an exhaust system is from scratch, I promised myself there that I would never make another one again, although that’s what I’ll be doing for my new build! I now had a good, powerful and sorted cobra but still had the need to tinker with it so started looking at other options. I decided I needed a larger throttle opening on my plenum to give me more power, so went to J.E. Developments and spoke to John about it, he fetched me an enlarged plenum from his storeroom and told me to try it, if I liked it then to come back and pay for it. I did just that the following week! I drove the car like that for quite a while until I once again wanted more power, and whilst on one of my many visits to John Eales he introduced me to a full Jenvey RV8 throttle body set-up for an attractive price which I couldn’t resist. With that fitted I saw my cobra return over 307bhp at a rolling road organised by the V8 forum!
I felt I had reached the end of my power upgrades to this lovely Rover engine and decided that to get more power I’d need to go for American muscle which is why I am now building an AK with a highly tuned Chevrolet 383 cubic inch fuel injected throttle body powered cobra replica.