Cylinder Heads for a 7.3

[slvrwrx]

I swapped my 7.3 for a 6.9 after some cracked piston heads and loss of compression. I saved the heads from the 7.3 thinking i could port them and clean them up real well to flow better, and then swap them on my 6.9. Unfortunately, the 7.3 has one additional head bolt, so it wont work on my 6.9. Anyone need em? Ill let them go cheap, and theyre fully assembled and working good.

 

[79jasper]

Extra head bolt?
You're crazy.
Only difference is head bolt size. Lol

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[slvrwrx]

Are you sure? What's the head bolt differance?

 

[cpdenton]

7/16th head bolt size on a 6.9.

1/2 inch on a 7.3.

Both should have 17 bolts if I remember right.

 

[icanfixall]

Both the 6.9 and 7.3 have the same number of head bolts. You will have no problem using the 7.3 heads on the 6.9. You will need to modify the lower corners of the 7.3 heads so they have a water passage like the 6.9 has. Just look at the 6.9 head gasket and make the same size holes in the 7.3 plugs. You really don't need to remove the plugs either. Just drill a hole. Look closely at the other block water passages hole size compared to the head gasket hole sizes.

 

[slvrwrx]

Both the 6.9 and 7.3 have the same number of head bolts. You will have no problem using the 7.3 heads on the 6.9. You will need to modify the lower corners of the 7.3 heads so they have a water passage like the 6.9 has. Just look at the 6.9 head gasket and make the same size holes in the 7.3 plugs. You really don't need to remove the plugs either. Just drill a hole. Look closely at the other block water passages hole size compared to the head gasket hole sizes.

so if i modify the coolant passages just a little bit, the head will drop right on to my block? and also, at that point id be putting arp head bolts, and what size bolts would i want to get, the 6.9 size, no?

 

[79jasper]

For the 6.9.

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[icanfixall]

I feel your wording is off a bit. Head bolt from ARP I feel is not what you mean. Are you saying bolts instead of studs?? We listen and need to know what your talking to really be able to help you. A 6.9 engine will require the 7/16 head bolts or studs no matter what. A 7.3 requires the 1/2 inch head bolts or studs. Your 7.3 heads will fit the 6.9 and you can use the 6.9 head bolts or a set of ARP 6.9 studs. I'm hoping the information help you.

 

[slvrwrx]

I feel your wording is off a bit. Head bolt from ARP I feel is not what you mean. Are you saying bolts instead of studs?? We listen and need to know what your talking to really be able to help you. A 6.9 engine will require the 7/16 head bolts or studs no matter what. A 7.3 requires the 1/2 inch head bolts or studs. Your 7.3 heads will fit the 6.9 and you can use the 6.9 head bolts or a set of ARP 6.9 studs. I'm hoping the information help you.

Indeed my wording is off a bit. Its been over 2 years since ive had the motor apart, and Ive dealt with alot of engines since then. Studs then, the heads held on by studs. Youve been really helpful so far, thanks. so my only question is, if the 6.9 block is threaded for the 7/16 studs, that means the head, since its prepared for 1/2 studs, am i going to need to take up that extra 16th in each hole somehow? or will it stay centered good enough?

my plan is to take these 7.3 heads, port them up a bit to get some more flow, and then remove my 6.9 heads from my running truck, and put it back together with new headgaskets and arp studs ( 7/16 size right?)

feasible?

 

[icanfixall]

Yes it feaseable. The 6.9 & 7.3 heads both align with the same size alignment dowels or pins. Depends on what everybody calls them. They are all the same size and fit the heads and blocks the same. They are the top outside head bolt hole location. Nothing is needed to make up the small differences in bolt size either.

 

[BDCarrillo]

ARP 200-8598 (10 pack) or 200-8597 (2 pack) is an insert washer kit that is meant for 7/16 head bolts in 1/2 holes. Fit should be great since 7.3 head bolt holes are 0.545" They really help distribute the clamping force of the smaller 7/16 hardware to the machined face meant for 1/2 hardware. I used them to mount GT-40 heads on a 302.