75gmck25
Full Access Member
- Joined
- Oct 13, 2016
- Posts
- 2,266
- Reaction score
- 2,209
- Location
- Northern Virginia
- First Name
- Bruce
- Truck Year
- 1975
- Truck Model
- K25 Camper Special TH350 NP203
- Engine Size
- 5.7
I used aluminum Blueprint H8002K heads, which run $899 complete with valvetrain. You can buy new Vortec heads for about $700, but depending on what else you plan to use with it they may need to be modified. I planned to use a roller cam with lift that was borderline too high for stock Vortec, so aluminum heads that were already set up for a roller and higher lift seemed like a better choice.
Going to 64cc chamber heads will get you about 1 point more compression (8.2 up to 9.2?), and I used a thinner head gasket (.026 instead of .039) to get it up to about 9.4.
I have seen the suggestion in the past to try 305 heads, but I would do a thorough internet search for information before trying that route. Some think it works well, while other think its just about the worst choice available.
I am using a cam with duration of 213/217 @ .050, which is a good match for my engine compression and the weight of the truck. I have a TH350 with stock converter, 4.10 gears and 31" tires. You will find many guys who go for max horsepower by using a much higher duration cam, but what you give up is torque/power that comes in a low RPM. You need torque to get the truck moving and make it feel strong. With long tube headers my combination should be good for about 350 HP, but I am still running stock iron manifolds and duals, so i give up about 20-25 HP.
Bruce
Going to 64cc chamber heads will get you about 1 point more compression (8.2 up to 9.2?), and I used a thinner head gasket (.026 instead of .039) to get it up to about 9.4.
I have seen the suggestion in the past to try 305 heads, but I would do a thorough internet search for information before trying that route. Some think it works well, while other think its just about the worst choice available.
I am using a cam with duration of 213/217 @ .050, which is a good match for my engine compression and the weight of the truck. I have a TH350 with stock converter, 4.10 gears and 31" tires. You will find many guys who go for max horsepower by using a much higher duration cam, but what you give up is torque/power that comes in a low RPM. You need torque to get the truck moving and make it feel strong. With long tube headers my combination should be good for about 350 HP, but I am still running stock iron manifolds and duals, so i give up about 20-25 HP.
Bruce