I would like to put out my A-Code engine horsepower from 225 to ~300. For this, i'm changing some parts in the first step (I already ordered but not install yet)
1) Intake manifold Stealth dual plane
2) Holley 4160 600 cfm carburetor with electric choke
3) MSD Pro-Billet Ready-To-Run Distributors (MSD-8352)
4) MSD Blaster 2 coil
5) Street fire ignition wire set (8 mm)
i'll change headers and camshaft in the second step.
End of the day, does my engine performance up-to 300? If your answer is Not, what can i do for more horsepower.
Regards
With exhaust (including headers) you'd probably happy with that setup, I would think. The Stealth/Holley combo is a good one. A cam might not be necessary for your purposes.. .the above setup will probably outrun a K-code if the exhaust is done right (SAE Gross... see below). Don't go too big on the exhaust... for your purposes 2.25" pipes, and headers with 1 1/2" primaries might be ideal (generally its easier to find 2.5" pipes and 1 5/8" headers though.. going bigger will hurt your lowend but help a bit in upper rpms).
Also, keep in mind (explaining this gets tiresome, but I feel it must be done)... horsepower was rated differently in 1966 as opposed to today (actually, its changed a couple times... the 60s are even more confusing because manufacturers intentionally fudged ratings for insurance reasons). Without getting much into detail, in the 60s horsepower was rated in SAE Gross units. Now its rated in SAE Net units. The difference has to do with the test method and what accessories are connected to the engine when its tested (i don't remember all the specifics).
Bottom line, its doubtful that a 225 hp 60s Mustang would make the same #'s on a dyno as say... well any 225 hp car today. Its been a while since I've seen a chart, but most stock 289s put down 140-160 rwhp in stock trim, IIRC. This comes out to ~190-200 SAE Net hp at the crank, about 10% (which is roughly the rule, from what some old dude on a Mopar board used to tell me) less than the original rating. This difference starts getting bigger as engines get wilder.
To get to a true, honest 300 hp, you may need a camshaft upgrade. But I'd do the other stuff first and see if you're happy. The stealth/holley/exhaust will give you some growing room if you decide to get more aggressive (all will work well with aftermarket cams and heads if you decide you need it).
(part of me is telling myself that getting into the SAE Net vs. Gross issue might be overkill, but I had it typed out so figured Id might as well)