Big Block Chevy Aluminum Cylinder Heads - Bare
300cc Intake Port, 119cc Chamber, Oval Port
Pair (2) of big block Chevy ProComp aluminum cylinder heads. These heads are bare and ready to assemble. Comes with features normally found in heads costing much more, including:
-
Hardened exhaust seats for unleaded fuel compatibility
-
Bronze valve guides
-
Manufactured with aircraft quality high grade aluminum alloy
-
Multi-angle seat design for improved flow at low lifts
-
Advanced port design for improved flow at all lifts
-
Advanced combustion chamber design allows superb flame travel and burn
-
Additional pushrod clearance machined along outside port walls
-
Threaded accessory holes in ends of heads
-
Retains stock intake/exhaust bolt locations
-
Thick deck to resist warping and allow for additional milling if desired


|
Intake Port Volume
|
300cc (oval)
|
|
Combustion Chamber
|
119cc
|
|
Intake Valve Size
|
2.250" *
|
|
Exhaust Valve Size
|
1.880" *
|
|
Valve Stem Dia.
|
11/32"
|
|
Intake Port Size
|
1.8" W x 1.95" T
|
|
Exhaust Port Size
|
1.9" W x 1.65" T
|
|
Spring Pocket Dia.
|
1.730"
|
|
Exhaust Crossover
|
No
|
|
Plug
|
Angle
|
|
Weight (per head)
|
28 lbs.
|
Flow Numbers
|
Intake Flow
|
Exhaust Flow
|
|
.100
.200
.300
.400
.500
.600
.700
|
74.3
166.11
245.36
308.05
339.84
360.43
374.31
|
.100
.200
.300
.400
.500
.600
.700
|
62
118
160
195
229
248
265
|
* +.250" long intake, +.100" long exhaust valves required
|


|
These heads are a great choice and at a great price, you will not find this kind of quality for the price we have them listed at. Perfect for everything from street, marine, and in any other performance/race application where a quality head at an affordable price is desired. A great upgrade from OEM factory heads. These heads are a better alternative compared to the rectangle port version if you aren't runnning a big stroker engine or all out race application, you'll get much better low end performance. They should handle up to about 600HP in as-is form without much problem. Further gains can be had with gasket matching and porting techniques.
Aluminum material allows the benefit of higher compression ratios on the street compared to iron heads, not to mention how much weight they save compared to the factory cast iron ones! These ProComp big block heads have been tried and tested for a few years now with excellent results.
We also carry these as a fully assembled pair ready to bolt on. Check out our store for more cool products including other head selections including the rectangle port version!

|