Because I had some bad luck with the 403 in my Wagon lately, I decided to go the extra mile right now. I've been thinking of putting early 350 heads (68-72) or 330 heads on it for a long time.

Recently I started getting problems with the engine. After running fine one day, I could not get it running again the next day, for the life of me. It turned out to be the timing chain had slipped. Thanks to that nylon stuff that's on the cam gear, and the chain itself was pretty worn after 31 years of service.
After replacing the timing chain set and putting everything back together I heard a loud ticking noise when I got it running again. I still had the valve covers off and could see that the exhaust valve on the #2 cyl. wasn't doing anything. It just stayed closed. So I figured that noise was a little backfire every time the #2 cyl. fired. I could see that the pushrod was a lot deeper into the hole than all the others. Like the lifter or cam lobe was gone. I pulled the intake that same night. And discovered the lifter came apart. The little spring and that cup the pushrod sits on were laying in the intake valley. I had the rockers off when I was replacing the timing chain (easier to turn the cam by hand). I also took all the pushrods out to clean everything. I think things really came apart at that point. Anway, I ordered new lifters. And I'm also going with a new cam. I bought a RV cam, this one:
http://www.hdmaddog.com/Oldsmobile/C...-p3677433.html

Has anyone ever used this one? Any thought? I think it's at least a step up from the stock cam. And my car is a station wagon, it's not a race car but it could use the low end torque.

What is the best break-in procedure for these engines? Any tips on what kind of lube or motor oil I should use for the break-in?

Since I had to pull the intake anyway, I decided to go with an Edelbrock Performer now. I got a good deal on a used on on Ebay. Gonna bead blast it when it get's here, paint it and put it on. It's the #3711. Does anyone know if it's higher than the stock intake?

I'm also thinking of putting other heads on it lol, since I'm at it anyway. Now is the time!
I know you can put 68-72 350 heads on a 403 to bump up the compression. But you can also use 330 heads right? I can get my hands on a set of 330 heads. They are #3 heads (1966, 389394). Can anyone tell me how much cc the chambers are? I've seen/heard 60 and 65 cc. What is it? I want to do some compression calculations.

I know I have to drill the bolt holes from 7/16" to 1/2".
What else is involved for installing 330 heads on a 403?

Oh and any tips on where to get parts would be nice too. I know Mondello. Any other Olds parts vendors?

 

65 cc's.
To use #1,2, or 3 heads on a 403, you will have to clearance the pushrod holes because they came off of an engine designed with a 45 degree lifter bank angle in mind. The 403 has a 39 degree lifter bank angle. The holes for the pushrods will be off. Using these heads without clearancing will make a mess of the pushrods, and your oil. You must either grind the bottom of the pushrod holes in the heads with a high speed grinder, or oversize drill them, so they clear.

To install early heads on a 403, there are things you MUST do, and things you should do.
*Note above if they are 330 heads...
*You MUST drill the head bolt holes oversize (17/32nds)
*You MUST drill the 3rd alignment pin hole in the head to 5/16ths. Neglecting to do this means the head will not bolt down on the block.
*Use 403 head gaskets
*Use the pushrods that match with the rocker arms. Early 350 push rods, and rockers have small cup ends, late 403's use large ones. Do not mix early/late push rods and rockers!!!
Things that you don't have to do, but you reeeeeeely should. Just short of neglect.
*A GOOD valve job. Guides, and seats can cost big power, used components (what...100k miles???) NEED attention.
*2 inch intake valves. That's what the factory put on the 403, why put heads on that use a 1.88 intake. Open the bowls up.
* Surface the heads. I usually cut mine around .030" to not have to deal with intake alignment, and for a little more compression boost.
*Hard exhaust seats for life in a desert climate. My opinion, but I have seen too many out here with trashed exhaust seats.

Do not complain about cost. Most people do (it is duly noted, there was no complaining in above paragraph) whine about cost of reworking parts. Then they skimp on things that will make a BIG difference. Please do not do that.
You should jump your compression a bit more than a point, so the camshaft may need to be different.

Vendors are here!!!
http://72.22.90.30/phpBB2/viewtopic.php?t=2021

I personally, like Mark Smith at MJ performance.

I also like Jim Lapikas (403 guru!) at J&S machine.
http://www.jsmachineoldsmobile.com/

Good luck,
Jim

 

Thanks for your reply, Warhead!

The heads that I'm thinking of using a #3 330 heads. I can get those from a guy I know, and for a good price.

I am familiar with head porting and have the grinder tools and bits.
I should widen the bottem end of the pushrod holes?

Yes, I'm going to do a valve job and everthing. I want to properly rebuilt the heads (I work at a machine shop ).

Thanks for all the additional info and list of Olds verdors! Awesome.
My questions for now are answered.

Last night I picked up a set of Olds smallblock headers. Hopefully I get those heads soon and the rest of the parts so I can get to work! I want this 403 running again!

I'll use this thread to ask more questions if I run into something.

 

Nooooo. "Widen" infers width. The hole does not need to be widened. Where you will need additional clearance is on the bottom of the hole, opposite side from the intake manifold face.

It is best if you do the clearance work before you strip the heads. That way, location of excess material, actual grind work, all trimmings can be removed by the cleaning operation.

Another option is to have the bottom of the push rod holes opened up to 9/16th, for about 1 inch up from the bottom.

Jim

 

Time to fire up this old thread again! I finally got those 330 heads a few weeks ago.

I already started stripping, cleaning, painting and porting them. Not all the porting work is done yet, but here are some pics so far: here

I already ordered new valve guides, seats, seals, new ARP headbolts and a Comp Cams roller rocker kit (#1442) and all the gaskets I'm going to need for this head/cam/intake swap.
This saturday I plan on drilling the headbolt holes to the correct size. Aswel as the bottom of the pushrod holes, 1 inch up from the bottom, like you mentioned, Warhead. Seems like a good option.

I work at a machine shop and I work on cylinderheads all the time. So I can do all the work myself. I'm going to install hardened exhaust seats too. Probably the intakes too while I'm at it. At work I can get a wide variety of valve seats. I might start with cutting away the existing seats saturday if times allows it.
For cutting the actual seats (3-angle cut) I have to replace the valve guides first of coure. Or things might be off. We have a great Serdi cutter at work.

Just one thing I have to ask for now, which one is exactly the 3rd alignment pin hole?
If you take this picture for example:

You count from the front of the engine?