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bb heads
found a leak doing a leakdown test
pulled heads to replace head gaskets are gm castings 353049 heads with alum lunati rockers any good thought i would have valve job done while off anything i should have done at the same time of work being done on heads? |
head
049 and 781 are chevys best early oval port heads Mild cleanup under the valves is worth alot for the effort if your looking for more power
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head
forgot to add bigger valves help a bunch also
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Make sure you have the heads pressure checked. I didn't on my last set and found out later the guides were leaking water. So I had to rip the top half of the engine down in the boat because I wanted to save a few buck. Learn from my mistake.
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does anyone know the spec of these heads ? or where i can find them
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Here is some info I found on the web a couple years ago. I think it is reasonably accurate. It lists the 049 casting as having 122cc chambers.
Chev Big Block V8 Cylinder Head Casting Numbers CASTING#.....YEAR...PORT TYPE.....ENGINE SIZE 330864.....68-84...oval...OPEN...396, 402, 366T, 427T, 454 Truck 330865.....68-84...oval...OPEN...396, 402, 366T, 427T, 454 Truck 330866.....68-78...oval...OPEN...366T, 427T 330867.....68-73...oval...OPEN...427T 336765.....68-78...oval...OPEN...427T 336768.....73-76...oval...OPEN...427T 336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports 343771.....68-86...oval...OPEN...366T, 427T, 454 343772.....68-86...oval...OPEN...366T, 427T, 454 343783.....70-76...oval...OPEN...454 Truck 346236.....75-87...oval...OPEN...454, 120cc chamber, 225/116cc ports 352625.....70-76...oval...OPEN...454 Truck 353049.....73-84...oval...OPEN...454, 122cc chamber, 255/119cc ports 366765.....74-78...oval...OPEN...427T 473328.....68-69...oval...OPEN...366T 3856206....65-66...oval..CLOSED..396, 97cc chamber 3856208....65......rect..CLOSED..396/425hp, 109cc chamber 396/375hp "Z-16" Chevelle 3856213....66-82...oval..CLOSED..366T, 427T 3856260....68......oval..CLOSED..396 Truck 3872702....65-66...oval..CLOSED..396, 427, 98cc chamber 3873858....65-67...rect..CLOSED..396, 427, 109cc chamber 3876875....77-85...oval...OPEN...427T 3904390....67......oval..CLOSED..396, 427, 98cc chamber 3904391....67......rect..CLOSED..396, 427, 107cc chamber 3904392....67......rect..CLOSED..427, Aluminum, L88, L89, 107cc chamber 3904393....68-76...oval...OPEN...366T 3908952....67......oval...OPEN...427, "M.Truck", Marine 3909802....67......oval..CLOSED..396, 427, 101cc chamber 3917215....67-68...oval..CLOSED..396, 427, 101cc chamber 3917219....68-85...oval...OPEN...366T, 427T 3919840....67-69...rect..CLOSED..396, 427, 107cc chamber 3919842....68-69...rect..CLOSED..396, 427, Aluminum L88, L89, 107cc chamber 3931063....68-69...oval..CLOSED..396, 402, 427, 101cc chamber 3933148....69-84...oval...OPEN...'69 396/265hp, 366T, 427T, 112cc chamber 3933149....68-76...oval...OPEN...427T, 122cc chamber 3935401....68-76...oval...OPEN...427T 3946074....69&71...rect...OPEN...'69 427 L88, ZL1, Aluminum, 118cc chamber '71 454 LS6, "round exhaust port" 3964290....69-70...oval..CLOSED..396, 402, 427, 454, 101cc chamber Large or small hex spark plugs used 3964291....69-70...rect..CLOSED..396, 402, 427, 454, 109cc chamber Large or small hex spark plugs used 3965198....68-69...oval..CLOSED..396 Truck 3975950....68-70...oval...OPEN...396, 402 Truck, 366T, 427T 3986133....68-85...oval...OPEN...366T, 427T, 454 Truck 3986135....69-73...oval...OPEN...366T, 427T 3986136....68-84...oval...OPEN...366T, 427T, 454 Truck 3993820....71......oval...OPEN...402, 113cc chamber, 255/114 ports 3993820....71-84...oval...OPEN...454 Passenger and Trucks, 113cc chamber, 255/114 ports 3994026....71......rect...OPEN...454 LS6, 118cc chamber 3999241....72......oval...OPEN...402, 454, 113cc chamber 6272292....70-78...oval...OPEN...402, 454 6272990....70-up...rect...OPEN...454 service replacement, used on some MKIV crate engines, 118cc chamber 10045427...........rect..........Pontiac/Chevy Aluminum, 91cc chamber Large Port, race 10049875...........rect..........Pontiac/Chevy Aluminum Small port, race 10051128...........rect..........Bowtie, Aluminum 72cc chambers Symmetrical ports 10051129...........rect..........Bowtie, Aluminum "raw" casting, Symmetrical ports 10052902...........oval...OPEN...MkIV, 427T 10101140...91-up...oval..CLOSED..Gen.V 366T, 427T 10114156...91-up...oval...OPEN...Gen.V & VI 454, 118cc chamber 10141279...96-up...oval..CLOSED.."Vortec 7400", 100cc chambers 10487052...77-90...oval...OPEN...366T 12363391...96-up...oval...OPEN...Bowtie, Aluminum, Signature Series, fits MKIV, Gen.V, Gen.VI, 110cc chamber 12363401...96-up...rect...OPEN...Bowtie, Aluminum, Signature Series, fits MKIV, Gen.V, Gen.VI, 118cc chamber 12558162...01-up...oval..CLOSED..Gen.VII,"Vortec 8100", 8.1L, 496, truck 12560241...98-up...oval..CLOSED.."Vortec 7400", 100cc chambers 12562932...91-95...oval...OPEN...Gen.V, truck crate motor, 118cc chambers 12562934...00-up...rect...OPEN...Gen.VI 502 Marine 14011077...69-up...rect...OPEN...Aluminum, fits MKIV, "C-port" 118cc chamber, also sold as a "solid" head 14044861...84-96...rect..........Bowtie, Aluminum, MkIV, "raised runners", 1st design, 105cc chamber 14044861...96-up...rect..........Bowtie, Aluminum, Signature Series, fits MKIV, Gen.V, Gen.VI "raised runners", 2nd design, 115cc chamber 14044861...84-96...rect..........Bowtie, Aluminum, MkIV "raw" casting of "861" MKIV 1st design 14081045...78-87...oval...OPEN...454 14081052...85-87...oval...OPEN...366T, 427T, 454 Truck, Marked "HiPerf" 14092359...86-90...oval...OPEN...366T, 427T, Marked "HiPerf" 14092360...86-90...oval...OPEN...454 Truck, "peanut" round ports 14096188...70-71...rect...OPEN...454 service replacement, also used on later Mark IV LS-6, LS-7 and 454 HO crate motors, 116cc chamber 14097088...91-up...rect...OPEN...Gen.V 454/502 HO, 118cc chamber 24502585...97......rect..........Olds/Chevy, DRCE 2, Pro Stock aluminum, for blocks w/4.900" bore spacing 25534404...04......rect..........Olds/Chevy, DRCE 3, Pro Stock, aluminum, for blocks with 4.900" bore spacing T = Tall deck Oval includes both "peanut" (also called "round") ports and large oval ports |
thanks
with that being said what cam would be in the motor ? |
Are they the factory heads? I think GM stopped putting the 049/781 on engines in the early 80's. I'm guessing here but I'm pretty sure you have a 330 engine, so its a small cam (213/217 duration). Now if someone swapped the heads your cam could be anything.
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Originally Posted by endeavour32
(Post 3859048)
Are they the factory heads? I think GM stopped putting the 049/781 on engines in the early 80's. I'm guessing here but I'm pretty sure you have a 330 engine, so its a small cam (213/217 duration). Now if someone swapped the heads your cam could be anything.
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If you can measure your lift, we might be able to give you an idea of what you have. The 454 Mag and 330 engines have different lift. What year are the engines?
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