Chevrolet "Open Chamber" Cylinder Heads
15 to 25 Horsepower Improvement
If your rules require the use of “open chamber” heads, the ‘441, ‘487 & ‘993 heads work the best. While these heads are not available new from Chevrolet we have an excellent supply. |
"UnderCover Ported" '993 Head  |
Our "UnderCover" Porting will improve the air flow of stock open chamber heads from 203 cfm intake and 142 cfm exhaust to 225/230 cfm intake and 160 cfm exhaust. This air flow improvement will result in a 15 to 25 horsepower improvement while maintaining a stock looking port!
Our Complete "Open Chamber" Heads Include:
* Pressure tested and magnifluxed castings
* "UnderCover" Ported * Machined for screw-in studs
* Pushrod holes opened * Bronze Guides are installed
* Flat Surfaced to your specifications * ARP Rocker Studs & Guide Plates
* 5000 series Ferrea valve * Steel Retainers & Machined Locks
* Competely Assembled
If your rules do not allow screw-in studs or opening of the pushrod holes, we can supply a set of heads without this work.
| Part # |
Description |
Price |
| LMS-441-UC |
Complete ’441 heads, with "UnderCover" Porting, 5000 series Ferrea valves, 1.250" springs & flat surfaced to your specifications. |
$1,995.00* |
| LMS-487-UC |
Complete ’487 heads, with "UnderCover" Porting, 5000 series Ferrea valves, 1.250" springs & flat surfaced to your specifications. |
1,995.00* |
| LMS-993-UC |
Complete ’993 heads, with "UnderCover" Porting, 5000 series Ferrea valves, 1.250" springs & flat surfaced to your specifications. |
1,995.00* |
| 434PHX |
* Add larger 1.440" o.d springs and 6000 series Ferrea valves to compete heads. |
165.00 |
| 434P-H5 |
* Add Ferrea Hollow Stem valves to complete heads in place of Ferrea 5000 series valves. |
375.00 |
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See full details about our complete head assemblies. Check out a list of options for our complete heads. |
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Our bare '441, '487 & '993 heads start as quality pressure tested and magnifluxed castings. They are then machined for screw-in studs, pushrod holes opened, solid bronze guides installed and honed for proper clearance, "UnderCover" Ported and a Serdi valve job designed for the open chamber heads is performed. |
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| 441-UC |
’441 castings, bare, machined for screw-in studs, bronze guides and with "UnderCover" Porting. |
1,495.00 |
| 487-UC |
’487 castings, bare, machined for screw-in studs, bronze guides and with "UnderCover" Porting. |
1,495.00 |
| 993-UC |
’993 castings, bare, machined for screw-in studs, bronze guides and with "UnderCover" Porting. |
1,495.00 |
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