1972 chevy truck k20 brakes and exhaust.?

I hate to say this but you should have it towed somewhere with a pressure bleeder. I say this for 2 reasons. Reason 1 these are your brakes were talking about its the only way to stop your truck so I believe that since you have never done it before you should have a professional do it. And reason 2 every good tech knows that brake fluid absorbs water so if someone put it in your brake system then that’s why you should get it pressure bled so they can flush out all the water. Make sure you tell them that there is water in the system and that it needs flushed extra good. This may not be what you wanna hear but its a professionals opinion.

First, the Brakes. You need to replace all damaged lines FIRST. Second, if any of the water got into the front calipers, or the rear wheel cylinders, you need to flush them out. Best thing to do would be to take them off, remove the bleeders, and let them either soak in brake fluid over night, or blow them out with air (think safety) then reassemble.

Once everything has been repaired, and your wheel cylinders & calipers are clean, DO NOT reconnect your lines (yet). You need to fill the master cylinder and let the brake fluid flow out of the lines. This is called gravity bleeding, and it gets all the contaminates out of your brake lines.

I assume that you mastercylinder was never depleted of fluid? If so, you will not need to bleed it. If it has been “sucked dry” then you need to bleed your mastercylinder before you work on the rest of the system. Yo ucan get bleeder kits at any parts store.

If your master cylinder is good, and you have flushed out the lines with new fluid, then reconnect all of your lines, open ALL bleeder valves, and fill your resivior again. You need to gravity feed the system with the calipers and wheel cylinders connected.

Start closing the bleeders starting with the caliper closest to the mastercylinder, and work your way AWAY from the master cylinder (while keeping the fluild flowing while you are closing the bleeder valves.

Refill the master cylinder. NOW you are ready to bleed the system. Starting with the wheel FURTHEST from the mastercylinder, have a helper pump the brakes, and then crack the bleeder valve. Repeat this until you no longer get any air. Then move the the next closest wheel – periodically checking the master cylinder level. Repeat at each wheel until you are done with all four wheels. Top off your master cylinder, and you should be done with that part …….

The advice to take it to a pro is sound, but you dont strike me as someone that wants to let everyone else work on your truck, and with the labor involved, you would be spending a lot of money for something that you could do anyway. These old trucks dont really need a lot of fancy tools to work on them either.

MORE POWER: I had a 1968 C-10 with 4 wheel drums. I had a 350 in my truck. I ran an HEI, Edelbrock 650cfm carb, Edelbrock intake, headers, and dual exhaust with Flowmaster mufflers.

If you want more power out of your combination, you need better flow through your heads. You have touched everything else (carb, intake, cam) – this is all that is left. This means bigger valves and smoother bores which will increase your air flow. With bigger valves, you will not reach your full potential unless you match a different camshaft with a longer duration and higher lifts. Be advised, changing your camshaft means you effect EVERYTHING in the engine. Timing, valve adjustments, idle speed, and the need for MORE fuel.
If you are running an automatic transmission, a stall converter will help with more torque, which will help you launch harder with more RPM, but if you tow, or haul anything, you will be taking from that ability. I would not advise you go this route on a daily driver.

If you are not getting above 160*, and you are not running a fan, then I would question your cooling system, or your temp gauge. You have the right radiator, but your engine isnt getting warm enough, and is more than likely running cold (ie NOT making all the power it can). Change your thermostat to a 180* and run a hotter sparkplug to get more “spark”. This will make more fire in the cylinder, and make a little more power. Double check your timing, and make sure you are running 8mm plug wires or better.

FYI: I used Autolite #26 sparkplugs in my truck for more than 15 years with the HEI.

You want to take care of all the small things before you go after more power gains. If you use this truck for hauling or towing then you need to run a trans cooler on any automatic trans. You will also need to look into a vacuum canister if you get too radical with the cam because that will effect your transmission shifts (automatic only).

If you are not running headers already, that is good for 15hp alone. DO NOT run straight headers, you will be deaf in a week if this is a daily driver. Your neighbors will hate you, and the tickets are not worth it.
DO NOT run straight pipes either. John Law knows what it sounds like, and your valves will not have any back pressure. Yes, it will run great for a while, AND it will be very loud. It the cost to this is early cylinder head rebuilds. Proceed as you wish.

For your small block to live (and be happy) you need air flow. The more air you can pump into your engine, the more power it will make. This will require better exhaust flow.

Start small, and work your way UP to the more expensive upgrades. Timing needs to be spot on. Hotter spark, proper cooling, better exhaust flow and efficient fuel delivery. Dropping your mechanical fuel pump and running an electrical pump frees up horsepower too.

A common mistake with upgrading to HEI on the older trucks is not having 12 volts to the coil on the HEI. The truck will run, but it will not have all the power that it could have (because the spark isnt as hot as it should be). Its something that needs to be checked. You can also run a hotter coil.

With the serpantine set up, I dont know what water pump you should be running. A simple check is to open your radiator cap and ensure that coolant is flowing into the radiator. If that is happening, you are good to go.

Fuel Octane, spark, spark delivery, and exhaust all need to be their BEST to make power.

GOOD LUCK