I have a ‘77 403 and saw a pair of bare #7 heads locally for under $200
I do not have immediate rebuild plans, and would do a mild build, if ever just to add some pep to the 403.
Should I grab them while I can?

 

I would. They are only get harder to find and probably not get any cheaper.

 

Yeah, go for it. Visually inspect for cracks and overall condition. Expect to put $1000 into them.

 

Is that CAD? But yeah I suppose close between valves and springs.

Need to drill head bolt holes on a mill to 17/32 for your 1/2" head bolts.

Cut them .020" to make up for the difference in the thicker head gasket. Factory is ~.018", replacement FelPro is ~.042"

For a cheap thrill, get your smelting pot out and melt a few hundred cans or a few pistons down and block the exhaust crossover.

 

[QUOTE=brownbomber77;1419869]Is that CAD? But yeah I suppose close between valves and springs.
In our funny money, even more if all new guides, valves and springs were used.

 

Thanks for the advice fellas. They are already set up for bigger valves and have brand new guides in them. 1 side is VERY crusty, gonna have to clean it and see if I got an ok deal on 1 head or a good deal on 2.
Paid $125 and a 6pack
I will have to get the head bolt holes machined, do not know about the dowel sizing.
I had a neighbor check a couple dimensions with his calipers. Intake was just under 2" (1.996 or so) and exhasut was around 1.6XX (can't recall offhand) and bolt holes were just under 1/2".
Seats are new looking, saw some casting flash so I don't think any porting has been done. Exhaust crossovers are empty, can I use the Edelbrock plugs and move on? I live in Houston so not needed -- as it is I have to use a 1/2" spacer to keep vapor lock away.

just so we're all on the same page -- this is a bone stock '77 403 Vista Cruiser w/TH400 and the legendary 2.56 rear end. It also came with the factory adjustable air-ride so that's neat. Would be neater if it worked (running on a crappy Amazon air shock hose kit currently)

Performance mods include tires that hold air, upside down air filter lid, and side pipes (only reason I bought the car honestly).
That said, I'm not building a bracket racer or anything crazy, it cruises pretty damn nice at 80mph and I like the feel of the car but looking for some bolt-on stuff to satisfy my tinkering urges.
Current thoughts are: 2711 intake, the #5 heads, maybe the "RV" cam. Long-term, low bucks as possible. Maybe get that ET down from high 18's to a respectable 17.80.

 

You should be in the high 8 to low 9 to 1 compression, about 1 to 1 higher than stock with those #7 heads. Did the machine shop use a cutter under the larger valves? One dowel on each head just needs enlarged to 5/16", very simple. If you have a drill press, just use a 1/2" drill bit. The 204/214 "RV" cam is OK, it is best to be degreed when installed. I don't remember seeing those mid 70's Olds wagons that I recall, on the road, a lot of weight to move.

 

That is beautiful. I also see you're a man of good taste and class with the LeMons windshield sticker.

You would probably benefit most from a gear change while you're in there. Cheapest would be a 77-96 B Body wagon. I'm fairly confident the spring perches are the same distance on the A and B body wagons. You just can't get it from a sedan or just relocate the spring perches another 1.5" outward. Great thing about the wagons is many of them came with a towing package, a 3.23 (albeit cone-style) posi. Otherwise, a 2.93 or 3.08.
Don't bother with the 2711 unless you're just looking to take off 30 pounds from the front end. Get yourself some eBay headers, bang them up for fitment, remove them, clean 'em up and shoot them with high temp. I would hope given the side pipes that it already has headers though.
Ford Motorsport E351 and B351 pedestal mount roller rockers bolt into place onto our engines without changing the pushrods also.

 

Cleaned up okay. Not sure if the pics answer the question of enlarging the bowls but I think they were. Exhaust crossover remains but the center ports are welded.

 

They look good, a deal for sure, the bowls look opened up. The 7111 is a better intake, the problem is finding one, 2711 is still available. CC the heads if you want to figure out your exact compression ratio.

 

Is there a place to measure the heads and compare to “as cast” specs to see how much it has been milled already?

Also regarding 2711/3711 vs performer RPM intake, why the RPM over the others/factory? Asking to learn, not argue with people who know their stuff.

My thought process here is to bump up my highway cruiser a tickle over time. I like taking her out on 100+ mile trips on interstate/back roads 60-80 mph cruising. That is why I was looking at the Performer 350 vs RPM as a “better than stock but not a race car” top end refresh.

 

Use a piece of plexiglass over the chamber. Drill a hole and add light oil, washer fluid or water with a measured CC syringe. The Performer RPM is 2 " taller plus the larger plenum and longer runners increase power production along with it's larger in size runners than the 2711/3711.

 

Use a piece of plexiglass over the chamber sealed with vaseline. Drill a hole and add light oil, washer fluid or water with a measured CC syringe. Then you have a CC number. The Performer RPM is 2" taller plus the larger plenum and longer and larger in size runners increase power over the 2711/3711.

 

I did them and they are around 70c
Obviously my methodology is wrong but they are consistent and not too tiny (plenty of meat left I guess).
exhaust valve spring seat seems lower than intake.
setup for 2” and 1.625 valves

 

That should put you around 8.75 to 1 with the .042" compressed Felpro head gaskets. Of course that depends on the piston to deck measurement. About a 1 to 1 gain. I believe the #7 heads have uneven spring pockets. Maybe throw a good straight edge on the tops of the valves to see if the valves have the same installed height. Installed height is critical for the factory non adjustable valve train.

 

There's another issue -- it's bare and I got no parts. I snagged a pair of valves based on measurements for testing and used an old spark plug. The service manual for the '77 403 shows a damper in the exhaust spring, no indication of rotators though they are mentioned in the reassembly.
I will be removing a valve cover this weekend to take a peek at what I've got already.
Am I overthinking this? Grab some new springs, keepers and a shim set to get to 1.670" re-using retainers and rockers from 4A heads?

 

Don't bother with the rotating retainers. Just use or get non rotating. You can use a positive valve stem seal from a 90s small block Ford without modification or if you have the Comp tool, just cut the guide down to .500" for a positive style seal.

 

Good to know about the 90's SBF valve seals fitting factory Olds guides. My #6 heads were cut for the .500" positive seals, they work quite well. In your case, get something like the 5812 Edelbrock valve springs, if you can find them and buy regular retainers. Pretty sure 4A heads have rotator retainers but it has been a few years since I pulled apart those turds.

 

Thanks for tips @brownbomber77 and @olds 307 and 403 here are some pics of the guides.


The base is 1/2”diameter, top of the guides are level, valve spring bases are not. Quick and dirty measurement of valves to retainer lock area look right at the 1.670” ballpark.
it looks like “most” of the work has been done, I just need to get the heads cleaned up and checked before I put together the final list.

Low bucks:
Existing rockers and retainers from 4A heads
Existing pushrods from 403
Stock springs (Melling 720 I think) and keepers
Positive lock seals (or umbrella?)
Stock intake and cam
Shim kit

Medium bucks:
Ford roller rockers and studs, 403 pushrods
Positive lock seals (or umbrella?)
Edelbrock 5812 springs
New retainers, non rotating
Shim kit
Stock intake, maybe RV cam

All the bucks (pipe dream):
True rollers, requires machine work
7111 intake machined and RV cam
Positive lock seals
Edelbrock springs, new retainers, shim kit

Limitations/Considerations:
The wife hates this car, if it’s down for more than week I could end up homeless. I won’t go “bigger” than the RV cam.

Looking to build better but not “beyond” my setup if that makes sense while having fun tinkering with my son.

Separate beef, if 1 more person at a cruise tells me about the 403 windowed mains or an LS swap I’m gonna lose it. This car has never gone over 3500 rpm in gear.

 

Yeah, the LS isn't my thing either, completely useless if idle to 3500 is your thing. I hate them below 3500 stock in GM's trucks. Without a cam swap, the basic Melling valve springs will work fine, probably even with the RV cam. The rocker arms, if not worn excessively should also work along with the current push rods. The factory cam gear is nylon coated and they can fall apart and get sucked into the oil pump pickup. I have used a couple of the 204/214 RV cans with the stock valve train. Even with thicker Felpro head gaskets, they worked fine. My Wife didn't much like my 88 Cutlass and in the end, I didn't much like it anymore either. The 70 is a different story for both us and why a small fortune is going into it. Good luck.

 

The timing chain issue solved itself when the chain fell off at the Mexican border. If you’ve ever wondered how many Oldsmobile timing sets are available 90 miles west of Del Rio,TX on a Sunday afternoon, the answer is 0.
The wife’s major complaint is no AC in Houston (that will be addressed independently).

Do those guides look set up for the positive lock seals or just go with umbrellas that have held for 45 years?

 

Yes, the guides look cut. Take a caliper, they will probably measure close to .500". Parts for these cars aren't on the shelf anymore, isn't that true. If the timing set is done, you can leave the cam. No A/C down there would be killer. I couldn't stand 40C just like you guys wouldn't want our -40.

 

 

I agree with the above, especially if you have done the timing set with the pan in place in car. They are PIA to get the cover back on, so you are obviously capable. I assume a cam can be pulled and installed in car with that front end? Honestly doing new pan gaskets and neoprene main seal aren't bad ideas while tearing the motor half apart. Pulling the engine is required or lifting the motor somewhat. Then you could also do a mild converter swap if desired to replace the 1600 factory stall. The #16 iron intake is fine for what you want but heavy. If you want to save a few bucks, go that route. A 2711 is the least gain for money spent.