dp73115

I have a 1968 383 in my 1973 Challenger. I am wondering what options I have to increase the horsepower. Here are the facts on my engine: 1968 HP 383, 292-509 MP CAMSHAFT, 0.30 OVER FORGED PISTONS, 906 HEADS, ELDEBROCK RPM INTAKE, and a 750 CFM DUEL LINE HOLLEY connected to a 727 auto with 2800 rpm stall converter. Any suggestions?

jh27n0b

What is your compression ratio? Are you wanting to replace components? What kind of exhaust system are you running? Headers? The carb seems a little big for stock heads. Have you thought about aluminum heads? How about a nice stroker kit? Try these guys. http://www.440source.com/ These are a lot of questions but how far are you willing to go and what is the purpose of the vehicle? Street or strip or a combo? You should be able to easily get a streetable 400 hp but it is going to take some component swapping. The 383 is a very good engine but there is no replacement for displacement.
Bob

lear4406

Seems like you have done the major stuff and nice componants. What gear are you running and have you installed a MSD type system for your ignition? Also look at the whole exhaust system 2 1/2" to 3" with headers. Also tail tips that look factory but have the 2 1/2" to 3" opening. Fuel line 5/16? You need 3/8". Your Challenger was a small block so it came with the 5/16" line. Also need the 3/8" pick up. All these can be found on E-Bay Motors. Heads are where its at and the 906s are a good factory head. But they need work to make big #s. Also did you upgrade the springs in the head when you put in the 509? There are some really free flowing heads done in aluminium by just about everyone. Spark plug wires and plugs are also a good upgrade as well as a real cool motor. Aluminium radiators are a good inveatment as well as a 170 thermostat. I hope this helps.

dp73115

Thanks for the replies.. My gear is a 8-3/4" with 3.55 posi and my cylinders have been bored .030"
I think I have made most of the modifications mentioned except for switching to aluminum heads. I converted the fuel tank to a sump and use a Holley fuel pump pushing through 3/8" SS fuel lines, mallory ignition system, 2-1/2" twin exhaust from Hedman headers through flowmaster 2-chamber mufflers and I have a aluminum radiator. I guess I just needed someone else's opinion that I have done the obvious things already. Options now are heads or to make a stroker.

lear4406

Seems like you got it covered