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head swap
https://www.slantsix.org/forum/viewtopic.php?t=7387		 Page 1 of 1
Author:  sixty4dartgt [ Wed Oct 29, 2003 6:53 pm ]
Post subject:  head swap
I want to put a post '68 head on my car (as per Doc's article).
Here's my questions:
1. I read that my engine (1964) was rated at 145 hp. A 73 engine was rated at 105 hp. If I use a '73 head, will it drop my hp ?
2. How do I know if the '73 van I'm pulling the head from has a 225? It could be a 198, right? Does it matter?
3. Anyone ever heard of or used a thinner head gasket to "cheat" some compression? If so which one?
If not, which gasket should I use? Where can I get it?
Sorry for all the questions, but my car is dead in the driveway right now and I'm dyin' over here !!! :evil:
Author:  DusterIdiot [ Wed Oct 29, 2003 7:04 pm ]
Post subject:  Remember rating system changed in 1972...
Your car might be rated at 100hp in 1972+ terms.
They used to take the power figure by running the engine will all accessories bolted to it and turned on, from the rear wheel or something to that nature. Your engine was rated from the flywheel with nothing parasitic attached.

If you aren't going to 'cleanup' the deck an head with some milling, check how straight they are and you might have to use a comp. gasket like a fel-pro to keep it all sealed.

-D.Idiot
Author:  jsbgraphics [ Fri Oct 31, 2003 6:43 am ]
Post subject: 
Hey, you might want to check out this page in the articles section as well.

http://www.slantsix.org/articles/sa-fra ... hapter.htm

I read through these the other day and it goes into allot about what is interchangable, and some of things to look out for.

Hope this helps
Author:  addo [ Sat Nov 01, 2003 1:28 am ]
Post subject: 
This is a common enough question on other brands as well. :wink: I can throw a few "generalisations" at you:

People often get precious about the old style shim gaskets. It's easier and cheaper to buy an off-the-shelf new Fel-Pro or whatever quality brand is local.

Yes, you will have to skim the head to compensate for the difference in thickness. But only once; then you can always use the newer, cheaper, equally good gaskets. Milling might also help adjust the CR to be where you want it.

As for the 198 vs 225, I can't comment. Typically, manufacturers used the same head if possible and varied piston dishes in these scenarios. Easier to have different pistons than heads in stock.

A little knowledge doesn't hurt. CC the old head as it comes off, and the new one. CC the piston dish in similar fashion, and run the lot through a compression calculator. Don't forget to factor in your overbore (this raises the CR).

This CR calculator comes from Dave and Dennis Schjeldahl, I6 gurus. :D Just type in all your values and play around.
http://falconperformance.sundog.net/compcalculator.asp

Incidentally - there's a lot of information you can glean from the motor with the head off - timing gear wear, bore size, deck height, piston dish, cam timing... Don't rush through and miss something that could help you later.

Regards, Adam.
Author:  sixty4dartgt [ Sat Nov 01, 2003 8:26 am ]
Post subject: 
Thanks for the feedback. I'm gonna try to get into this weekend. I got a '73 head for $35. It's kind of a coin flip, but I am out of cash. :(
Author:  Doctor Dodge [ Sat Nov 01, 2003 10:53 am ]
Post subject: 
I agree with addo, don't rush to swap one used head for another.

First-off, the 73 head will swap over with no problem and it does have the better combustion shape and induction hardened exhaust seats.

If it were me, I would beg / borrow a valve spring compressure and take the 73 head apart, clean it, check for serious problems like sunk valve seats, worn-out guides or cracks. (Visual checks)

If the head is OK, give it a quick clean-up port and bowl porting job then take it to someone for a resurfacing. When you get it back, hand lap the valve seats and re-assemble the unit with new stem seals.

If the head is in good condition to start, all this can be done for around $100.00 ($50 for the resurface, $35 for a gaskets and stem seals and $8.00 for some lapping compound - Other can "chime-in" with better costs / price info, this is my best estimate)

I would also be sure the car is running or you clearly understand why it does not run, before you swap the head.
DD
Author:  sixty4dartgt [ Sat Nov 01, 2003 9:18 pm ]
Post subject: 
I have already installed the head.
However:
I did take it apart, check for cracks, clean it, replace the valve stem seals and use the grinding compound.
:P
BTW, I got a Fel-Pro "torque it once" gasket for $28.
I understand what you are saying , but I really can't afford the time or money. I am over budget in both cases.
Let's hope the head is straight !
Thanks again for the input. I would be putting in a V-8 if it wasn't for this site. :shock:
P.S. How do you post pics ?
Author:  sixty4dartgt [ Sat Nov 01, 2003 9:21 pm ]
Post subject: 
Another thing is the reason I changed the head is I had a busted stud and then busted the Easy-out in the same hole. I figured I would have to remove the head to get it "burned out". It was cheaper to get another head (if it's straight) and I could "upgrade " at the same time.
Author:  slantzilla [ Sun Nov 02, 2003 6:58 am ]
Post subject: 
Last I knew, the steel shim head gasket is still available form Dodge for about $7. :shock:

I've got some out in the garage, if you want I can go dig up the part number. :D
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