the venerable pinto has plenty of tuning scope, just depends on what you want, i dodnt think a 180 bhp 2.1 pinto in a camper would make for a pleasent trip round the cotswolds

if you are after more torque (puling power) you would be better with a v6, if you want more mpg you need a 2.5 d, petrol engined vans quiter but more thirsty, diesels more economical but louder than petrol. you have to way pros and cons. but in mean time find a carb / manifold off of a sierra cortina or capri, may need some setting up though, another good bet is a 4 branch manifold gets rid of the awful standard cast exhaust manifold, try a web search for capri care at drayton parslow near bletchley, he may be able to help you in your quest for a little more go!