360 LA installing Promaxx Aluminum heads
Street car only, 74 Challenger. Previous heads were rebuilt stock cast from a longblock that has less than 15k miles on it. Was running ok, just felt like it needed a bit of help to get the performance up a bit. Hydraulic flat tappet cam, .450/.450~110 LSA~218 Dur @ .050. Was punched out .030 when rebuilt.. Moly rings & dished pistons. I would have needed to remove the AC and a lot of other stuff to get the thump stick out in the car and I was not interested in pulling the block. If the block ever comes out it's going back in a 408. Instead I went with a 1.6 ratio roller rocker (stamped stock rocker probably 1.46) that will ramp faster and add about .030 lift. Better flowing closed chamber 63cc heads with bigger valves that should bump the compression from low 8 or less to nearly 9.2. And a new Air gap intake. Should be a hummin' lil 360 with good street manners. Guesstimate at the crank... neighborhood of 400HP and 450TQ, all done by 5500rpm. I could probably squeeze a bit more if I installed longtube headers but I'm not interested in all that would entail. It had Hooker longtubes on it when I bought it and ground clearance was a whopping 2 inches... I bottomed out on everything. I'll stick with these TTI shorty's for now as they make life sooo much easier.
Have a brand new fiberglass TA hood (will be painted matte black after fitment)that will be going on as soon as I get the engine squared away. Here is a shot from when the wife and I drove it out to Monterey last March.
Street car only, 74 Challenger. Previous heads were rebuilt stock cast from a longblock that has less than 15k miles on it. Was running ok, just felt like it needed a bit of help to get the performance up a bit. Hydraulic flat tappet cam, .450/.450~110 LSA~218 Dur @ .050. Was punched out .030 when rebuilt.. Moly rings & dished pistons. I would have needed to remove the AC and a lot of other stuff to get the thump stick out in the car and I was not interested in pulling the block. If the block ever comes out it's going back in a 408. Instead I went with a 1.6 ratio roller rocker (stamped stock rocker probably 1.46) that will ramp faster and add about .030 lift. Better flowing closed chamber 63cc heads with bigger valves that should bump the compression from low 8 or less to nearly 9.2. And a new Air gap intake. Should be a hummin' lil 360 with good street manners. Guesstimate at the crank... neighborhood of 400HP and 450TQ, all done by 5500rpm. I could probably squeeze a bit more if I installed longtube headers but I'm not interested in all that would entail. It had Hooker longtubes on it when I bought it and ground clearance was a whopping 2 inches... I bottomed out on everything. I'll stick with these TTI shorty's for now as they make life sooo much easier.
Have a brand new fiberglass TA hood (will be painted matte black after fitment)that will be going on as soon as I get the engine squared away. Here is a shot from when the wife and I drove it out to Monterey last March.
