Another head question
#1
Racer
Thread Starter
Another head question
According to one of the leading mail order suppliers, these heads are not compatible with my 78 L48 with stock cam because I don't have the correct cam installed. These heads list for hydraulic cam only, he said I have a flat tappet cam. I responded yes, but it is still a hydraulic cam. This guy is full of crap....correct?
I chose these because they will accept the performer intake and perimeter style bolt valve covers.
Brand:
PROMAXX Performance
Manufacturer's Part Number:
2151
Part Type:
Cylinder Heads
Product Line:
PROMAXX Performance Vortec 185cc Iron Cylinder Heads
Summit Racing Part Number:
PMX-2151
Cylinder Head Style:
Assembled
Cylinder Head Material:
Cast iron
Cylinder Head Finish:
Natural
Combustion Chamber Volume (cc):
64
CNC-Machined Combustion Chamber:
No
Intake Runner Volume (cc):
185cc
Exhaust Runner Volume (cc):
60cc
CNC-Machined Intake Runner:
No
CNC-Machined Exhaust Runner:
No
Intake Port Location:
Standard
Exhaust Port Shape:
Square
Exhaust Port Location:
Standard
Spark Plug Style:
Straight
Intake Valves Included:
Yes
Intake Valve Diameter (in):
2.020 in.
Exhaust Valves Included:
Yes
Exhaust Valve Diameter (in):
1.600 in.
Valve Springs Included:
Yes
Maximum Valve Lift (in):
0.575 in.
Outside Diameter of Outer Spring (in):
1.270 in.
Damper Spring Included:
Yes
Retainers Included:
Yes
Retainer Material:
Steel
Locks Included:
Yes
Lock Style:
Stock
Valve Stem Seals Included:
Yes
Rocker Arm Studs Included:
Yes
Rocker Arm Nut Thread Size:
3/8-24 in.
Rocker Arms Included:
No
Rocker Arm Nuts Included:
No
Guideplates Included:
Yes
Guideplate Pushrod Size:
5/16 in.
Valve Cover Mounting Style:
Center and perimeter bolt
Accessory Bolt Holes Drilled:
Yes
Valve Guides Included:
Yes
Valve Guide Material:
Manganese bronze
Valve Seats Machined:
Yes
Valve Seat Machine Style:
5-angle
Valve Seat Material:
Ductile iron
Steam Holes Drilled:
No
Oiling Style:
Through pushrod
Machined for O-Ring:
No
Heat Crossover:
No
Quantity:
Sold as a pair.
Notes:
For use with hydraulic cam and lifters only.
I chose these because they will accept the performer intake and perimeter style bolt valve covers.
Brand:
PROMAXX Performance
Manufacturer's Part Number:
2151
Part Type:
Cylinder Heads
Product Line:
PROMAXX Performance Vortec 185cc Iron Cylinder Heads
Summit Racing Part Number:
PMX-2151
Cylinder Head Style:
Assembled
Cylinder Head Material:
Cast iron
Cylinder Head Finish:
Natural
Combustion Chamber Volume (cc):
64
CNC-Machined Combustion Chamber:
No
Intake Runner Volume (cc):
185cc
Exhaust Runner Volume (cc):
60cc
CNC-Machined Intake Runner:
No
CNC-Machined Exhaust Runner:
No
Intake Port Location:
Standard
Exhaust Port Shape:
Square
Exhaust Port Location:
Standard
Spark Plug Style:
Straight
Intake Valves Included:
Yes
Intake Valve Diameter (in):
2.020 in.
Exhaust Valves Included:
Yes
Exhaust Valve Diameter (in):
1.600 in.
Valve Springs Included:
Yes
Maximum Valve Lift (in):
0.575 in.
Outside Diameter of Outer Spring (in):
1.270 in.
Damper Spring Included:
Yes
Retainers Included:
Yes
Retainer Material:
Steel
Locks Included:
Yes
Lock Style:
Stock
Valve Stem Seals Included:
Yes
Rocker Arm Studs Included:
Yes
Rocker Arm Nut Thread Size:
3/8-24 in.
Rocker Arms Included:
No
Rocker Arm Nuts Included:
No
Guideplates Included:
Yes
Guideplate Pushrod Size:
5/16 in.
Valve Cover Mounting Style:
Center and perimeter bolt
Accessory Bolt Holes Drilled:
Yes
Valve Guides Included:
Yes
Valve Guide Material:
Manganese bronze
Valve Seats Machined:
Yes
Valve Seat Machine Style:
5-angle
Valve Seat Material:
Ductile iron
Steam Holes Drilled:
No
Oiling Style:
Through pushrod
Machined for O-Ring:
No
Heat Crossover:
No
Quantity:
Sold as a pair.
Notes:
For use with hydraulic cam and lifters only.
#4
Dr. Detroit
Member Since: Mar 2012
Location: New Braunfels Texas
Posts: 9,962
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The specs list a 1.270 spring for .570 lift....so yes, these heads will work for flat tappet.
Jebby
Jebby
#6
Wolf in Sheep’s Coating
Something to consider
I built a small journal 1967 327
Steel Crank only needed polishing, tough old cranks.
Rods, I used Eagle I Beam
Pistons. Forged 30 over Kieth Black 10.5:1
Cam, better than stock but not too loopy.
On top I use factory yet ported, double Hump heads and factory Aluminum Intake and valve covers.
I done several build such as this to Chevy and Fords of the 60’s
so that the outside looks totally stock while the inside is anything but.
I built a small journal 1967 327
Steel Crank only needed polishing, tough old cranks.
Rods, I used Eagle I Beam
Pistons. Forged 30 over Kieth Black 10.5:1
Cam, better than stock but not too loopy.
On top I use factory yet ported, double Hump heads and factory Aluminum Intake and valve covers.
I done several build such as this to Chevy and Fords of the 60’s
so that the outside looks totally stock while the inside is anything but.
Last edited by Opium Motors; 11-11-2023 at 09:56 PM. Reason: This was for the 327/300 build, somehow found its way here, please move
#7
Dementer sole survivor
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 16,397
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2020 C3 of the Year Finalist - Modified
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in the summit description is plainly states hydraulic flat tappet, so I dont know what the tech guy was thinking. THe other 2151 head is a 2151HR which is probably for hydraulic roller lifters but they dont provide a description for it
#8
Dementer sole survivor
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 16,397
Received 6,257 Likes
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2020 C3 of the Year Finalist - Modified
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2016 C3 of Year Finalist
the applications page lists it ...must be some gen z kid
https://www.summitracing.com/parts/P...ions/year/1978
https://www.summitracing.com/parts/P...ions/year/1978
#9
Dementer sole survivor
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 16,397
Received 6,257 Likes
on
3,904 Posts
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
it lists those as unavailable but heres some aluminum heads that are similar
https://www.summitracing.com/parts/e...make/chevrolet
https://www.summitracing.com/parts/b...make/chevrolet
https://www.summitracing.com/parts/e...make/chevrolet
https://www.summitracing.com/parts/b...make/chevrolet