[trunty]

My dad and I are upgrading to big block power in his 1-ton chevy trail/mud vehicle. We are wanting gobs (relative) torque as early in the power band as possible and have drafted this build. This is all on a 2-bolt 454 out of a '78 pickup and we are hoping for 400hp/500ft/lb of torque. Can any of you critique the elements of our build and do two things? 1. Estimate the output numbers and 2. suggest alternative elements for better power? Proposed engine specs are below.

Engine Summary
Goal: Bad *** stump puller
Engine Type: 1978 C-3500 454 built to a 460
Operating Range: 0-5000 RPM
HP/Torque: 400/500
Displacement: 460 Cubic Inch
Compression ratio: 8.7
Bore: 4.250” + 0.30” = 4.280”
Stroke: 4.00

Block
ID: GM 10T 861959 Hi Perf Pass
Production Year: 1978
Bore: 4.250” + 0.30” = 4.280”
Main Caps: Two-bolt

Cylinder Heads
Type: OEM 781
ID: 336781
Port Type: Oval
Combustion Chamber: 118 CC
Intake: 256 CC
Exhaust: 114 CC

Intake Manifold
Type: Edelbrock Performer
ID: 2161
Operating Range: 0-5500 RPM
Ports: Oval

Camshaft (Not sure about this cam...)
Type: Edelbrock Performer-Plus
ID: 2162
Operating Range: 1500-5500

Pistons
Type: Open to suggestions
ID:
Oversize: + 0.30
Stroke: 4.00
Compression: 8.7

Once again, any thoughts on the expected output numbers and critiques you may have are welcome. Also, even though this is a budget build is there anything relatively affordable that I missed that would be worth it? How would all of this hold up in a 2-bolt main? Worth machining it to a 4-bolt?

I realize my hp/tq numbers may be a bit optimistic/aggressive, however, I'm not sure.

Forgot to mention that we will likely be running hedman headers. Also, another cam we are considering is CompCams Xtreme 4x4™, X4 254H

Thanks again!

[matts37chev]

a little more compression will give it more grunt
two bolt block should be fine

[Torque454]

Those are about the numbers I am going for on my 454 also. Im thinking of a performer RPM cam, rpm air gap intake, performer 750 carb, 10:1 compression, also have 781 heads. Still not 100% sure on that cam but thats what I am thinking about.

[ndp]

Going to 9.5:1 would make a noticeable difference.