Tonyf

Cam OL 270/274~10H, dur @050. int 219. exh 226 LI 491 W/1.6. LE 499 W/1.6. Performer intake quadrajet built, roller tip rockers, #4 heads.

which heads are better 4, 7, or 7 with capital A but at bottom of the #7. Not 7A.

I welded up the divider and going to fill the crossover with melted pistons. What do I need to tell the machine shop to do to the heads. I知 putting 2.07/1.62 valves with harden seats.

where can I get a 6qt oil pan and extended pick up.

cutlassefi

5, 6, and 7a痴 are all about the same flow wise.
Will you be dynoing it?
Canton makes an excellent pan and pickup.

Tonyf

no I really don稚 any around except for Tony barker racing engines but he痴 a Chevy guy. On his site it saids Chevy and ford dynoing.

Fun71

The 7 and 7a (small capital A) are essentially the same. 7 was used in 1971 and 7a was used in 1972. Same flow rate, chamber volume, etc.

I am not as familiar with 4. They have larger combustion chambers and not quite as good flow rate on the exhaust side, but that can be rectified with porting.

maxi426

#4 heads have small chambers, and are about as good as any early head. If they're 4As they are the 403 head with large chamber and poor exhaust port. OP didn't say what pistons, but if stock dish the early heads will give a nice compression increase. With that cam, I'd be looking for a Performer RPM intake, unless it's a Trans Am.

fleming442

X2 on Canton pans- super nice stuff. Don't forget to plug the dipstick hole in the block; the pan has its own in the side of the sump.

redoldsman

I believe you will have to drill those earlier heads to accept the larger head bolts of the 403. But, you probably already know that.

olds 307 and 403

I have #6 heads with 2.07"/1.56" valves with the bowls opened on a 403. Even with the Performer intake, 204/214 cam and 2.78 open, it will annihilate the 275/60R15 tires. The 2350 stall did help. Are you keeping the stock 1600 stall and probably 2.56 gears? Are you upgrading to headers and dual exhaust?

joe_padavano

Yeah, but one at a time.

(Sorry, I couldn't help myself. )

olds 307 and 403

I was going to say that Joe😁. Oh and ﾗ3 on the Canton pan and separate dipstick, very well made.

Tonyf

I知 going with a 2400-2600 stall stage1 200r4, I知 keeping the 2:73 for now and it already has headers with 2 1/4 fail exh. I知 changing the headers to Thornton stainless headers and 2 1/2 exh.

Tonyf

Thanks for all the good information.
I bought a 403 with the 72 350 heads rpm intake. Guy said it was built by a machine shop, has cam, he said big cam. 350 rebuilt stock transmission with shift kit. 3000 stall. Came with brand new headers, collectors, mini starter, new regular starter, msd distributor but not every thing there he痴 going to look for the coil and control box what ever this is.
It痴 like the casino might win might lose.
I知 going to crank this one on a Break in stand hopefully a couple weeks. We値l see if he痴 telling the truth. If it runs good (lower end) I値l take the heads off and oil pan. I値l probably go ahead and upgrade this block with the stuff I mention originally.

olds 307 and 403

It will run around 1500 rpm at 60 mph, depending on tire height, with the converter locked and 2.73 gears. Yeah, a converter In that range will help launch. My 2350 flash stall is rated at 2200 to 2500 rpm and works OK with 2.78 gears and the 2004R. I just went from 1 5/8" Sanderson shorties and 2.5" X pipe exhaust with Dynomax Superturbo. Now has 1 3/4" full length stainless headers, 2.5" stainless duals with Flowmaster stainless straight through FX mufflers.

cutlassefi

You値l lose 25hp or by going from full length headers down to shorties, just an fyi.
And if you池e not going to Dyno it then buy a good wideband O2 and tune it right. It値l be the best money you ever spend.

olds 307 and 403

Mark, this why I wanted you to test those Sanderson I sent you, so we had proof for the Olds V8 on the power difference😉. I say the spread is more like 10 to 15 HP/TQ for full length. There was supposedly a test of the Thornton shorties, full length and maybe even their manifolds and showed a smaller gap between shorties and full length. Other makes with similar manifolds like SBD showed similar. I don't like the one dented tube on the Thornton SB version but like that existing down pipes can be used. Of course the Pypes down pipes are 2.25" then into 2.5". Ram Air Restorations no longer has the true 2.5" down pipes, last I checked their site. Does Flowmaster still make them? Of course, I had to dent the one pipe near the drivers mount on my 70S on these stainless full length. Ironically, a guy on the G body site put the full length stainless in a 87 with almost no modifications. Full length almost need tweaking somewhere but do make the most power. If ground clearance is currently an issue, shorties are the way to go.

Tonyf

I didn稚 know it be that much dang. I致e already bought the Thornton痴. I have problems with collectors leaking, can稚 stay in the car for exhaust fumes. What痴 O2?

fleming442

If it's just a street car, you won't miss 25hp anywhere but your brain.
A wideband O2 is attached to an AFR (air/fuel ratio) gauge. It is very handy when tuning a carb. I was told by Holley tech to use a vacuum gauge to tune idle, and my Brawler will see high 15-16 idling when cold. It levels out around 14.5 once warm.

Tonyf

I always use vacuum gauge to the highest vacuum.yes just a street car mainly just cruising and messing with mustangs lol

Tonyf

Lord I looked a wideband O2 up $500,
headgasket i afraid cometic because of block may not be clean enough, it痴 not going to machine shop heads are. 3247g Mr gasket or felpro? Suggestions

cutlassefi

AEM X series widebands are less than half of that and one of the most accurate on the market.
Vacuum gauge does nothing for tuning when you池e driving down the road.

olds 307 and 403

The AEM wideband worked great for tuning my Qjet. The Felpro head gaskets will work fine and are cheap. You should be right around 9 to 1 with a 65cc chamber.

fleming442

I didn't pay $500 for my AEM. Like cutlassefi said, about half that.
Personally, I'd be more worried about getting the thinner Cometics to raise the compression, if that's what stage you're in.

olds403

Those are 1967 Olds #4 heads as they came out of a 67 engine that I had here. That is what Tony the OP has above as the heads were cores at my brothers shop. I have had 4’s 5’s 6’s and 7’s. Mark did our 6’s and Terry at FCR did a 4’s as set for me as well. In a Trans Am the 4’s look stock and everything bolts up. Any SB head will too as we all know. As long as the valve train adjusts will be fine. The trans am is a PITA with shaker hood and BB heads with RPM. The aircleaner bases are unique to the trans am and the 77-79 400 bases are a fortune now. Then in a 403 you have to offset the shaker a F’up a perfectly good 400 shaker too. It is a $1000 nightmare easily. Mark had ONE of our custom spun bases that we shipped him. Unless you have done this - not simple with a 403 BB headed and functioning shaker,

fleming442

I don't think a few tenths off the head gaskets will affect the shaker that much.

Tonyf

Isn稚 the rpm intake taller than the performer? I have the performer on the TA now and the you can tell when you close the hood.

Tonyf

I have the performer on it now and it痴 really tight, the bows a little.

olds 307 and 403

Surprised the Performer is tight, it must just enough taller to make a difference. After getting those heads rebuilt, you will still be at least at 9 to 1 compression with around .067" piston to head with Felpro blue head gaskets. It depends if triple the Felpro price for Cometic .027" MLS head gaskets is worth it for .015" better quench. I would cut the Performer intake if you plan on running anything but the factory turkey tray or separate shim style intake gaskets. Honestly a check on straightness isn't a bad idea.

brownbomber77

Just built a set of #4 heads for a guy doing the same thing on a TA. I filled the crossover, cut them .030 to make up for the head thicker (.042 vs factory .017) gasket, installed 2.07/1.68 valves, and drilled the head bolts out to 17/32 on a MILL. Must be done on something rigid and square. Can't tell ya the intricacies of the shaker hood but it's been discussed on 78TA, Firebird nation, and Pontiac trans am forum pretty well.

#3 and early #4 will need to have the pushrod hole wallowed out a little bit with a tapered drill bit from Harbor Freight to confirm clearance with the pushrod (45* bank angle vs the later and more common 39*). But using #3 or #4 heads on a 403 with factory dish are better than later heads. Just a little smaller combustion chamber. Otherwise, slapping big valves in 5, 6, 7, 7a heads will get you to the same result.

Tonyf

how to tell if I have early #4? They池e off of a 67 330. I was told 39*

brownbomber77

I'm not sure. I remember running into this issue with a set a few years back or reading about it. I may be wrong in that all 67 were 39* however, in a Google search, Joe P made a statement in 2020

"Towards the end of the 1967 model year, Olds assembled some 330 motors using parts from the 1968 350 design. This is well documented in Dealer Technical Bulletin 67-T-19."

One way is to check the date code above one of the 3 head bolts on the exhaust side of the head

olds403

This is a non issue running #4 heads on a 403. The OP may have to address three minor things. Opening the head bolt holes, opening the push rod holes, and opening dowel pin holes. Any competent machine shop came do this work. Use the 403 head as guide. Most people have never seen 67 #4 heads. Not easy to find in early 2000 when I did it and harder now

Tonyf

Ok I bought an engine run stand and found a manual transmission bell housing. My original starter will not fit. I have a power master mini starter, it値l bolt up but will it work. Is there a manual transmission starter?
9785581 is the Gm bell housing.

olds403

No manual trans here, but this is the starter we use in all our builds and has some good diagrams

https://www.robbmcperformance.com/in...nIIstarter.pdf

fleming442

Did you drill the crank for a pilot bushing?
I didn't have much luck with the "conversion" piece. Starter is the same. Powermaster 9510 should work

Tonyf

I知 only using the manual bell housing for the test stand to bolt rear to the stand. I got the stand to breakin the camshaft when I do it. This engine I bought I want to crank it and let it run make sure the bottom is good. Then I値l put the #4 heads on and oil pan off to check bearings. Said it has about 800-1000 miles on it.

Tonyf

I知 using it on a Breslin test stand to crank and the engine. I致e got 9610 starter. The had a 9510 on the car. 9510 came with motor. It will bolt up, l didn稚 know if the drive will hit the bell housing

young olds

my 403 came out of a 77 full size Buick and accepted a pilot bushing and manual trans with zero work. I知 guessing it was machined from the factory this way.

brownbomber77

You didn't have to drill clearance into the back of the crank?

Which bushing? I tried the 690-023 and had to trim the OD ~.060 to fit into the end of the crank. Something like that, it was a long time ago.

Not sharp shooting, just would be good information for everyone to have for the bushing.

young olds

Stock replacement bushing, came with a clutch kit I bought years ago. All I did was tap it in as you would any other bushing, and I did not cut the input on the trans or drill the crank.

Tonyf

I see a few aem x which one do you think I need? 30-0300, 30-0334 and more.