[wk wood]

I recently modified a 1973 400-4 motor with 60k original miles. After my modifications, the engine feels flat, especially off the line. It feels slighlty more powerfull around 4000 RPM and then falls flat again around 4500 RPM.

I checked cranking cylinder pressure and it is only measuring between 115-120 PSI on all cylinders. This seems way to low! Based on the article I found at http://www.thepontiactransampage.com...blueprint.html. I am afraid my engine combination may never run to my satisfaction. Here are the modifications that I made, any insight or suggestions are welcome!!!

I swapped out the 4x heads for 1971 #96 heads (new valve seats, H.O. Racing's VS11 springs and 3 angle valve job). The chambers measured out at 96.5cc. I used a 71 cast iron intake, new Ram Air Restorations D-port exhaust manifolds and 2.5" exhaust, installed an HEI distributor (12 volt power sourced), and a Carb Shop stage II prepared Q-Jet. I installed a new Comp Cams XE262 camshaft (218/224, 110, .462/.470), 1.52 roller tipped rockers, Comp Cams pushrods, and their timing chain/gears. Initial timing is set at 16 degrees advanced, with total timing set at 35-36 degrees (vacuum advanced not yet hooked up).

I thought that had been careful in putting together this mild combination. It was my understanding that by using a Comp Cams Xtreme Energy camshaft that I would be able to maintain some decent cylinder pressure. My stock motor would have been around 135 PSI. Losing cylinder pressure is not what I expected!

By the way the car is a 1973 Grand Am (4300 lbs), 3.23 gears, stock converter, and will be driven daily.

Thanks in advance for any help!