True or False about 4.3 truck heads?

[flyboycj84]

OK275908, 97' 4.3 Gen LX

Pulled my heads after a water intrusion issue and sent em to valveshop....they say that portside is almost too bad to rework and recommends bringin in a head off a truck to rework.

Ive been told that 97' and above (vortec) truck heads are the SAME as marine, but must use a marine gasket....no prob.....junkyard has a gm van head for $58 and would def be nice on the budget.

Can i use the truck head??

Thanks!!!!

 

[smitty28]

Re: True or False about 4.3 truck heads?

yeah just make sure the cast numbers match and you should be good

 

[Struc]

Re: True or False about 4.3 truck heads?

^^ What he said

I have a complete block & heads from a 92 Silverado in my boat.

I didn't bother using marine head gaskets either. As long as your are in freshwater only, you can get away with using standard composite head gaskets too. I used a complete FelPro engine gasket kit putting mine together from Advance Auto Parts. I did use the marine exhaust manifold gaskets, though.

 

[tpenfield]

Re: True or False about 4.3 truck heads?

True . . . marine I/O engines are basically truck engines with a few variations.

 

[flyboycj84]

Re: True or False about 4.3 truck heads?

Great! Im in brackish/salt here in FL so i'll prob stick w merc gaskets.....this helps me get back on water tho without breakin the bank

 

[dearmosd]

Re: True or False about 4.3 truck heads?

I concur, making #s is a safe way to make sure you have the correct heads.

 

[Bondo]

Re: True or False about 4.3 truck heads?

OK275908, 97' 4.3 Gen LX

Pulled my heads after a water intrusion issue and sent em to valveshop....they say that portside is almost too bad to rework and recommends bringin in a head off a truck to rework.

Ive been told that 97' and above (vortec) truck heads are the SAME as marine, but must use a marine gasket....no prob.....junkyard has a gm van head for $58 and would def be nice on the budget.

Can i use the truck head??

Thanks!!!!

Ayuh,... There ain't no such thing as Marine heads,....

Heads are Heads,... Just match the Casting Numbers.....

 

[flyboycj84]

Re: True or False about 4.3 truck heads?

Sounds like good info that will save me a few bucks since it will be gettin a valvejob done anyway.....and hopefully get this damn boat back in the water soon!

 

[Struc]

Re: True or False about 4.3 truck heads?

There is a lot of good info about the 4.3l engine here:

Chevy V6 229,262,4.3 v-6 Engine Info & Performance

It will help you understand the differences between the different heads and casting numbers of the heads.

 

[Tail_Gunner]

Re: True or False about 4.3 truck heads?

Here you go all the info you need..

4.3L Rocker Swapping 101


1996 to 1999 All engines used a net lash system with screw in studs and self aligning rockers

?
2000+ All engines used roller trunion rockers. They were a net last system and self aligning.

Becareful when buying your head's as you can see the rockers can vary so you want to stay below the 2000 model yr

 

[79Formula]

Re: True or False about 4.3 truck heads?

I put a 96 4.3 out of a truck in a boat. I tore down the motor just to be sure. The new "mercury marine" head gaskets were in a GM Parts wrapper, and also had the same exact part number stamped as the truck ones. If i did it all over again, I would swap accessories, intake, and freeze plugs. Call it a day.

 

[flyboycj84]

Re: True or False about 4.3 truck heads?

Great info, thank u! Now i just need to find out which casting #'s match which trucks so Im ready for the junkyard!

 

[Tail_Gunner]

Re: True or False about 4.3 truck heads?

Dont worry about casting number's there all the same if they have a 8 bolt pattern. 113's are the latest heads but they have the roller trunion rockers. Now a good question would be do you need new pushrods for those trunion's they are a better rocker..Opps a opinion.

[/IMG]


That's a roller trunion 2001 head. notice that long steel girdel.

 

[Struc]

Re: True or False about 4.3 truck heads?

While I wouldn't argue with you Tail_gunner, I believe he's only replacing one head. That being the case, I'd match up the new head to the old, if for no other reason than parts similarity. There could also be other issues introduced with 2 different heads.

If replacing both, I would have no problem suggesting the newer style.

 

[flyboycj84]

Re: True or False about 4.3 truck heads?

ok...i looked at 2 pics i have of undersides of heads....dont have a full pic of the castings, but on the bottom of one head on what looks like the underside of exhaust tunnel is 113, which i assume coordinates with 12557113 that i believe is on the top. the other head says 107 on the bottom. now, the guy at machine shop said to find a 12557113 or a 12557140 to use.....so yes, at this point I am only trying to find (1) head to have machined to go with my good/rebuildable head that is at the shop. I guess one of my heads is too far gone for even a valvejob.

I do not have those roller rockers currently.....but you are saying that if I get 2 doner heads from, say, a 2000 or newer GM motor that HAS rollers, than I should just upgrade to those and get the doner heads valvejobbed? local junkyard has heads for $58 apiece and valvejob is $140.

Whaddya think?

 

[Tail_Gunner]

Re: True or False about 4.3 truck heads?

12557113 engines used 8 mm screw in studs and roller trunion rockers. They were a net lash system and self aligning. Casting 113 is for the self-aligning roller rockers, '99 and earlier heads won't work i have no clue why your 113 head's donot have that..

4.3L Rocker Swapping 101

Again that link should take you thourgh the step's 99 and back have a differnt rocker system so stay with 113 head they should be a dime a dozen


Ive re read your post..you seem to have a 97 head and a 2000 head on a 97 block someone modifyied the113 heads to work


Here a description for a merc 2000 engine...


STANDARD ROTATION, 175 & 205 HP, ROLLER CAM ENGINE WITH BALANCE SHAFT AND ROLLER ROCKERS, HAS 6 BOLT TIMING COVER AND 10 BOLT OIL PAN RAIL, HEAD CASTING NUMBER 113, BLOCK CAST # O9O.


In 97 i cannot find a 113 head cast number

 

[flyboycj84]

Re: True or False about 4.3 truck heads?

Well I guess I'll muddy the waters a bit....this motor is a remanned long block that was installed 5yrs ago. Cant remember at the moment where I got it, but the oem motor in my '97 SeaRay 185 blew up, and this is what went in. SO....you may very well be right...that something may have been modded on the long block. Im gonna hafta check the heads for myself when I get home, and see exactly what is on there. But the machinest said 113 or 140s will work. I guess this saga continues.

 

[Struc]

Re: True or False about 4.3 truck heads?

I'm pretty sure the casting numbers you're looking for are cast into the head on top (under the valve cover).

 

[flyboycj84]

Re: True or False about 4.3 truck heads?

@Struc.....thx for pic! The pix i put up are the only ones i had on iphone, im going to have to wait till I get home Monday to go check out the castings for myself, although I imagine the machinest read me those. Unless he was tellin me to look out for the 113/140 castings as replacements at the boneyard......hmmmm

 

[Tail_Gunner]

Re: True or False about 4.3 truck heads?

View attachment 179949View attachment 179945View attachment 179946Well I guess I'll muddy the waters a bit....this motor is a remanned long block that was installed 5yrs ago. Cant remember at the moment where I got it, but the oem motor in my '97 SeaRay 185 blew up, and this is what went in. SO....you may very well be right...that something may have been modded on the long block. Im gonna hafta check the heads for myself when I get home, and see exactly what is on there. But the machinest said 113 or 140s will work. I guess this saga continues.

It sure look's like someone put apr stud's in both heads...which were not factory in either head and self alinging rocker's..which head has all the rust in the intake's. Find a 113 head ot two and be done with it.