Round or Square Port Heads?

[ARAMP1]

I've got a 1990 TBI 454. I belive it's a Mark iv engine. I'm going to guess that the intake ports are round, but can someone confirm? I'd like to order some things without having it all apart while I'm waiting on parts. I guess if all else fails, I can just go to autozone and pick up a set of intake gaskets, which I'll need anyway.

 

[DEMON44]

ge the head casting #s and reference it. or I can.

 

[DEMON44]

well I can only see up to '85 anyways, but with the square ports being last produced in '71 I would assume round port, but I don't know where the peanut port falls in to.

 

[Jimbo*]

They should be the small round(peanut) ports, unless they have been changed.
Jimbo

 

[nvrenuf]

They should be the small round(peanut) ports, unless they have been changed.
Jimbo

+1

 

[54inches]

There was also a non-peanut oval port that year as well....

go to moretec.com or hotrodgossip.com and they have a list of casting and engine specs.....

 

[54inches]

Here ya go.......I erased all the non-454 BB stuff.



345014.....454.......70-86...
346236.....454.......75-76...2-bolt
359070.....454.......70-90...
361959.....454.......73-90...2 or 4 bolt


3963512....454.......70-76...2 or 4 bolt

3999289....454.......71-79...2 or 4 bolt, some "CE" replacement blocks had four bolt main caps

10051107...454...............4-bolt, Bowtie, MkIV, 9.8" deck, siamesed cylinder barrels, 4.25" semi-finished bores, can be bored to 4.50"
10069282...366T......90-91...4-bolt, Mark IV, Tall deck
10069286...454.......90-91...4-bolt, Mark IV, Short deck
10114182...454.......91-up...4-bolt, Gen.V


10134366...454T..............4-bolt, Bowtie, Gen.V, Tall deck
10185050...454...............4-bolt, Bowtie, Gen.V, Short deck
10237297...454.......96-up...4-bolt, Vortec 7400", "L-29" Gen.VI

12550313...454.......91-up...4-bolt, Gen.V crate motor, Gen. VI 4.25" bare block, fuel pump boss
12561357...454.......96-up...4-bolt, Gen.VI

14015443...454.......87-90...2 or 4-bolt, Mark IV, Truck, Motorhome
14015445...454.......78-90...2 or 4 bolt
14044807...454T..............4-bolt, Bowtie, MkIV, CNC prep, Tall deck, 4.25" bore or 4.495" bores

24502504...454...............4-bolt, Bowtie, Gen.V, Race prep, 9.8 "short" deck height
24502506...454T..............4-bolt, Bowtie, Gen.V, Race prep, 10.2 "tall" deck height
24502572.....................4-bolt, 4.5" bore Olds DRCE 2, 9.5" deck height
25534402.....................4-bolt, 4.590" bore Olds DRCE 3, 9.25" deck height



T = Tall deck, 10.2" deck height


1991 and later Gen.V, VI and VII production BBC motors have one-piece rear main crank seals.

 

[54inches]

Here's the head castings......


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....69-72...rect..CLOSED..396, 402, 427, 454, 109cc chamber, Large or small hex spark plugs used, crate motor usage in years after 1970.
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
12562933...91-95...oval...OPEN...Gen.V, 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

 

[k20]

If they are pretty much round, they are peanuts, otherwise, they are ovals. You can say with 90% certainty on big blocks of that era, they are peanuts.