Head confusion
05-07-2008, 07:08 PM
#1
Registered
Thread Starter
Head confusion
Ok guys, I'm looking to replace the heads on one motor in my Scarab 377. Engine package unknown but likely early bowtie 502 blocks. Head has a casting date of 1990 and casting number of 14096188. Casting reference charts say 1970-71 454 service replacement LS-6.
These are cast iron rectangular port heads. Could they really be 1990
heads that were originally for 454? What do I replace these with? Chev. dealership is very little help, said part was discontinued in 2004. Any info will be very much appreciated. Thanks. - Jeff
These are cast iron rectangular port heads. Could they really be 1990
heads that were originally for 454? What do I replace these with? Chev. dealership is very little help, said part was discontinued in 2004. Any info will be very much appreciated. Thanks. - Jeff
05-07-2008, 09:07 PM
#4
Registered User
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
http://www.offshoreonly.com/forums/s...d.php?t=185959
Not a bad head- probably nothing for you to gain by swapping for any of the newer GM heads- like the 088 or the 2932/3/4 heads which are the most current on the crate motors. They most likely are pre-1990.
Dart Iron Eagles will give you the best bang for the buck and will cost you less than replacement GM heads. They're probably as good as the Edelbrock aluminum's. You can find yourself a 75 to 100 horsepower bump by swapping to a modern aluminum head- like an AFR or Dart Pro1.
http://www.offshoreonly.com/forums/s...d.php?t=185959
Not a bad head- probably nothing for you to gain by swapping for any of the newer GM heads- like the 088 or the 2932/3/4 heads which are the most current on the crate motors. They most likely are pre-1990.
Dart Iron Eagles will give you the best bang for the buck and will cost you less than replacement GM heads. They're probably as good as the Edelbrock aluminum's. You can find yourself a 75 to 100 horsepower bump by swapping to a modern aluminum head- like an AFR or Dart Pro1.
05-07-2008, 10:30 PM
#5
Registered
iTrader: (4)
If nothing is wrong with them my $.02 I would not replace them.
If I was replacing them to get more HP I would sell the pair and take that money and buy some Dart Iron Eagles.
I ran the 188 and 088 GM rectangle heads for the last 6 years on my scarab, mine were reworked with 2.25" intake valves, and they were cut to 114.5 cc to bump up the compression.
I am in the process of putting on fully ported Merlin rectangle heads now and redoing my engines.
If I was replacing them to get more HP I would sell the pair and take that money and buy some Dart Iron Eagles.
I ran the 188 and 088 GM rectangle heads for the last 6 years on my scarab, mine were reworked with 2.25" intake valves, and they were cut to 114.5 cc to bump up the compression.
I am in the process of putting on fully ported Merlin rectangle heads now and redoing my engines.
05-08-2008, 07:52 AM
#6
Just something you might be interested in knowing.....for one reason or another the GM rectangle port cast iron heads are known for cracking between the seats at random. Dart Iron Eagles would be a better replacement head if you can afford to swing it. Otherwise, your just rolling the dice with the GM rectangle heads.
05-08-2008, 08:58 AM
#7
Registered
iTrader: (4)
Just something you might be interested in knowing.....for one reason or another the GM rectangle port cast iron heads are known for cracking between the seats at random. Dart Iron Eagles would be a better replacement head if you can afford to swing it. Otherwise, your just rolling the dice with the GM rectangle heads.
05-08-2008, 09:03 AM
#8
Registered User
That does happen but it happens on lots of other one's too.
Keep this in mind- there are more stock GM iron heads in use in pleasure boats than all of the aftermarket heads ever produced- by a big margin.
Keep this in mind- there are more stock GM iron heads in use in pleasure boats than all of the aftermarket heads ever produced- by a big margin.
05-08-2008, 09:22 AM
#9
Registered
Thread Starter
chris, kaama, rookie thanks a million for the info; i forgot to mention that i have broken(?) valve guides and a hole in a combustion chamber in one of the heads (not repairable) - just looking to put it back to normal condition - i'm just not sure if these (14096188) are the only ones i should use and also are these 454 heads really ok for my 502's. and again, chris thanks for your input, you seem to have a world of experience in all this stuff - i'm just a bit bewildered about all the heads that chevy made and what will and won't work. the more info from you all the better - jeff
05-08-2008, 09:44 AM
#10
Registered User
There was just a set of 088 heads on Ebay- Mercruiser- sold for $350. Those are the Gen V heads.
You can use the mark IV head with the proper mods- but why bother? There are lots of heads available. GM uses the same heads no on 454 and 502 engines- so that doesn't matter. One nice thing- the later heads use the o-ring valve covers.
heads are the cheapest, easiest way to pick up some horses- you're already in there- why not?
You can use the mark IV head with the proper mods- but why bother? There are lots of heads available. GM uses the same heads no on 454 and 502 engines- so that doesn't matter. One nice thing- the later heads use the o-ring valve covers.
heads are the cheapest, easiest way to pick up some horses- you're already in there- why not?
