looking for BBC heads casting #990
 

need three pair of heads for GEN IV motors casting number 990

Re: looking for BBC heads casting #990
 

You probably already know GM does not make them. Unless someone has some laying around used your in luck. Other option is to go for merlins.

Re: looking for BBC heads casting #990
 

I have 2 pair. 3 of them are cracked between the valves. Still interrested?

Re: looking for BBC heads casting #990
 

I Have A Pair Of Cast # 14096188 New Valves Perfeft Shape. Not Sure If They Are The Same. Ron Bender 216-390-1330

Re: looking for BBC heads casting #990
 

I also have a pair

Re: looking for BBC heads casting #990
 

posted on another thread GM does not make them but GM performance does or at least did GM and GM Performance are two separate operations

Re: looking for BBC heads casting #990
 

That is correct but the updated casting number is the 188. I bought a pair from Scroggin-Dickey Performance out of Texas. The specs are all the same just the casting number is different.

Re: looking for BBC heads casting #990
 

I have 1 pair oe 188s...cracked the same place.. :D

Re: looking for BBC heads casting #990
 

Thanks everyone i have plenty of cracked ones.

ScarabScoundroul how much for the one that is not cracked maybe this way i can make one pair for someone that needs a set.

i have decided to go with merlin heads. I am afraid that if this many are cracked their is a problem.

birdog are both of them cracked.

Re: looking for BBC heads casting #990
 

[QUOTE=guillermof]I have decided to go with merlin heads. I am afraid that if this many are cracked their is a problem./QUOTE]

Yep, and more than likely the problem is stock Merc risers/manifolds. That's what trashed mine.

Re: looking for BBC heads casting #990
 

The 2 pair that I have are ported and gasket matched. They are unassembled, but I have all the parts, including all the inconel exhaust valves. Let me verify the casting numbers tonight.

Re: looking for BBC heads casting #990
 

I have 2 sets of HP 500 gen 6 heads with 165 hours on them. No cracks if you are interested.

Re: looking for BBC heads casting #990
 

Yeah, they're definately 990's.

Re: looking for BBC heads casting #990
 

What are a pair of cracked 990's that are port matched worth?
What about the one that's not cracked?

Re: looking for BBC heads casting #990
 

ScarabScoundroul
i end up with four out of eight heads being good so i am set but thanks for the help.

Re: looking for BBC heads casting #990
 

Well that's good. So what is 1 good 990 head worth?

Re: looking for BBC heads casting #990
 

FYI the 990 castings have cast in valve seats and the 188 casting have pressed ln valve seats.The problem is that if the 990 heads need seats when the try to cut them out 9 times out of 10 you hit a water jacket.So in my opinion the 188's are better than the 990's for the simple fact that they are easier to rebuild.

Re: looking for BBC heads casting #990
 

I don't need a match. I replaced my heads last year. I'm only asking because someone else has found my head as a match to thiers. So I was wondering what I should sell it for. I had a friend that feels it's worth $300. ? ? ?

Re: looking for BBC heads casting #990
 

I have 1 990 head that is decent. Not rotted out , not ported, but needs rebuild. Make offer. Just threw four on the scrap pile Just went for New Dart. Beware of used dart heads. Early castings did not have the cast in struts where they eliminated the exhaust crossover, and are prone to cracking. Dart heads are cnc ported. They are heavy too. Really thick decks, etc... I couldn't believe the difference when I went to pick one up. BBB

Re: looking for BBC heads casting #990
 

BBB, what's it worth to you?

Re: looking for BBC heads casting #990
 

I Don't really know. Make a reasonable offer. I have to leave for work now. Get back to me later. I can take some pics and e-mail them. Maybe send a pvt msg. Also have a heavily ported 990, was cut for big valves and has solid bronze guides , slight cracks from whoever pressed guides. They were done with sealer. It's an automotive head . Super Clean!!! Threw it's mate out , had dropped valve and was welded, pinned basically whored up, and rendered useless. BBB

Re: looking for BBC heads casting #990
 

Talking about problems, Just went for a ride yesterday with my friend, Boat never ran better. Until it dropped a valve.
Head had a crack apparently , and water must have eroded the exh. valve stem. Definately going to go to Dart.
Guy's you must realize that these heads are not real heavy, add corrosion, deteriorization, decking, and porting work and I'ts a problem waiting to happen. The problem I feel is the boat comes out of the water for a second or too, the head heats up, and then get's shocked by cool water. This cycle happens over and over, and helps these heads to crack. I feel that a heavy aftermarket Marine head will take much more abuse than a GM 6272990 or equivalent. It's old(1971) technology that was great in it's heyday. They run great on street cars.