Suggestions on performance upgrades for 225

Nononononononono

I would stay as far away from Clifford as possible. From what I've seen/heard they are scam artists, are stupidly overpriced, and a lot of times will sell you wrong parts (mech cam instead of hydro, adjustable (mechanical) rockers with a hydraulic cam, etc) Not to mention that package is poorly put together/overpriced/not right for you. I'll explain.

The intake is good. If you plan on racing that is. Big plenum and large short runners make for poor torque, and in your van, torque is king. Plus, it is unheated. (water heated, but thats not near as good as exhaust heat when it comes to driveability)

Which Weber is it? Webers aren't bad per say, but the only 2 that I know of is the small progressive one and the 38/38(?) The small one is good for mileage but too small for any sort of performance gain, and the bigger one... Well, it may work...

Clifford's headers are actually some of the best ones out there. That ain't saying much though. The next thing is the put off a lot of heat compared to manifolds (not sure that'd be something you'd want in van), don't have the provision for plenum heat on the intake, may or may not work in your van, and may or may not provide a worthy performance gain in your application. Plus they rust.

The already built 'performance' slant may be worth looking into, but be very careful. Make sure it has a cam that isn't too big (I'd say no bigger than [email protected] if it were me, but that's opinion) and the proper compression ratio to match. Oversize valves would be a plus, and I'd want to run a cranking compression test if it were me. I would pay like it was a core engine if he didn't have receipts or proof of some kind though. Also, see who ACTUALLY built the engine (him, shadetree mechanic, proper shop, etc)

Also, the slantsix(.org) forum is worth your time for sure.