The first and easiest thing you can start out with is opening up the stock exhaust.

The stock muffler and dual cats are quite restrictive.

By running a high flowing muffler, and possibly high flowing cat, you can gain some otherwise wasted power.

single 2.5" piping should be the best size for velocity and flow on the 300.

 

So far,I think the #1 thing is the exhaust. Lots of ways to free it up. #2 MSD ignition. #3 egr restrictor plate. #4 cold air intake (home made). #5 cam. #6 head work. #7 remember its a truck and tractor motor not a 460. This is just my oppinion not exactly in that order. Of course this would be for the fuel injected motors.

 

I forgot about the #19 injectors and adjustable fuel regulator.

 

as far as inline performance goes you can

bolt on a set of headers/mufflers
bolt on a 4bbl 390cfm carb
cam
bore it .030 over
nos but only a 50 shot
there are topic regarding a turbo charger. please look for them

 

I really hope the sticky works. It's true that the same questions have come up repeatedly, and I may have been guilty of the same thing when I first found this site.

I'll try to recall some of the power mods for the 300....

Exhaust - 2 1/2" single OR 2 1/4 " duals have been suggested as the optimum system for a 300.

The "cat back" upgrades are great for opening up the exhaust side, and a relatively cheap (compared to a lot of engine modifications) - a GREAT first step for ANYONE. Muffler choises are a matter of many discussions - some prefer loud, some don't.

The 300 is notoriously "choked". Opening up the exhaust and intake does wonders - according to EVERYONE HERE who has done it.

Headers - there are several available. Clifford, Hedman, Hooker, come to mind. There are others.

EFI exhaust manifolds & a Walker downpipe are a nice upgrade for older carbed models with the stock, single outlet log exhaust.
The Part # for the Walker is 45166 and can be found several places for around $60. The Walkerexhaust website has a dealer locator service (free).

EFI manifolds from ANY EFI 300-6 ('87 and newer) will work on most older 300's and can be found at most junkyards for about $50 per pair. They can also be purchased NEW (Rock, others) but cost as much as some headers.

The 300 engine itself can be modified just like any performance engine. Bore, ballance, raise the compression. The short block is NO different in this respect.

The head, likewise, can be modified. Port, polish, mate, bigger valves (small block chevy valves - 1.94 intakes & 1.60 exhaust valves can be installed). 7/16" Screw in rocker studs can allow higher ratio (big block chevy 1.75) rockers. Again - no difference here - you can treat it like ANY performance head.

There are at least five cam companies that offer performance cams for the 300. Comp, Crane, Crower, Isky,...
Crane has the complete valvetrain and a user friendly website - www.cranecams.com.

Clifford and Offenhauser offer aluminum 2-4 barrel intake manifolds. You can get single plane, dual plane, water jacketed and non heated.

Carb upgrades are also available. 2 barrels are typically 350 or 500 cfm.. 4bbls range from 390 to 600. All have been reportedly used with success on the 300.

I don't know much about EFI upgrades, so I'll leave that to other members who are more experienced with them.

Currently, there are no turbo or supercharger kits for the 300, although some have done Do It Yourself. Bell's(Maximum Boost) and MacInnes'(Turbochargers) are two good books to read BEFORE you start asking a lot of questions.

You can NOX a 300. I'm not up enough on it to comment any further.

As mentioned by others, there are additional upgrades. Crane, Jacobs, MSD & others provide ignition upgrades. K&N, others offer high flow air filtration. Electric cooling fans save HP. Underdrive pulleys, etc.,
There are many of the normal performance upgrade options.

I'll think on this a bit more and post again if I think of something I missed, but that's it for now.

 

This thread will be for Performance Upgrades and or Tips and Tricks to adding more power to your Inline Six.

I have gone through the old "need more power again and again" thread and kept the useful information.

Please post only Performance Upgrades or Tips and Tricks for the inline sixes. All other posts will be removed. We want to keep this informative, easy to look through and straight to the point. No questions, conversations or general talk will be allowed. If you see things you want to know more about then PM or Email the person whom posted.

Thanks for your help on this and together we should be able to make a great Performance Sticky.