95 305 tbi runs great but lacks towing power

[rickpilgrim]

Found this 95 k2500 light duty with a rebuilt but non functional trans, fixed the pump and converter.
It's a 305 tbi/4l60e powered and the 305 is rebuilt and .040 bored and .010/.010 crank etc also.
Now I don't want to swap motor on this truck as stand alone trans computers and replacing the dash to a non ecm system ruins the budget.
Any ideas on getting 20-30 hp and torque out of a 305?
The second and 3rd pics are of the 408 sbc in my 92 K2500 LD.

 

[L31MaxExpress]

Try the simple stuff first...Check base timing and bump it to 4-6° BTDC with the EST connector unplugged. These engines like the upper end of the OE fuel pressure spec and some even more. 13-14 psi is where I have found many of them to run best and it needs to maintain pressure at WOT and WOT shift point. After the basics are checked, get some air to the air cleaner. Get the resonator less intake tube and build a powerbowl. Then add some headers and a dual 2.5" to 3" single exhaust with a high flow cat and straight through muffler like a Magnaflow. I have seen noticeable gains over and over again with a 1" open oval center TBI spacer and injector pod spacer. If they were not becoming so difficult or $$$ to find, I like the 454 aircleaner and inlet duct as well. This one is a 454 RV/Van unit, but the truck one is similarly massive in air inlet size compared to the small block.

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[GoToGuy]

In the stock engine dept, the 305 is like an orphaned step child. You need the 350. Or turn the 305 into a 383. More beans.
Low restriction air intake, headers, dual exhaust. There are electronic computer add-ons. Hypertek? One of those.
Good luck!

 

[L31MaxExpress]

In the stock engine dept, the 305 is like an orphaned step child. You need the 350. Or turn the 305 into a 383. More beans.
Low restriction air intake, headers, dual exhaust. There are electronic computer add-ons. Hypertek? One of those.
Good luck!

I have had several 305s. They were not a ZL1 Camaro by any stretch of imagination, but no problem pulling a 5,000 lbs trailer at 70 mph down the highway with my old LE9 305 G20 van or my L30 305 Vortec 99 Tahoe. Easiest and cheapest way to make more power in a small block is help it breathe and optimize the timing and air/fuel ratio. He could swap in a 350 but the same parts will still be choking it. I can get more power and better fuel mileage out of bolting parts on a 305 compared to swapping in a stock 350.

 

[Erik the Awful]

Any ideas on getting 20-30 hp and torque out of a 305?

You're in luck. I think that's what they made from the factory! Or are you asking for that much of an increase?

Start with the exhaust. Then make sure everything is tuned up and running right. A 305 can't afford to give up any horsepower to bad maintenance.