302 Head Question...
- Thread starter rgp266
- Start date
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Most if not all of the aftermarket intakes have the larger port openings. They are still compatable with small port heads though. Just use the small port gaskets. Some will grind the heads to port match or remove the majority of the step to improve flow.
At one time there were templetes available for port matching.
At one time there were templetes available for port matching.
C130 Chief
Mechanical Genius
All 66-up LA intakes are "compatible" inasmuch as they all bolt up the same. The difference as you know is the size of the port and runner, 318 heads being smaller.
There are 4 pretty common intakes for 318 sized ports; the regular Edelbrock Performer or Weiand 8007, both currently in production, and Edelbrock LD4B and Holley Street Dominator, both out of production. The LD4B is a good intake and still popular, a nice used one is worth $100 when you can find one. The factory iron dual plane 4 Bbl intakes were all large port. There was also an iron small port single plane 4 Bbl intake on the 273, and Edelbrock SP2P's are out there used. The last two are worth their weight in scrap and should be avoided.
You could certainly use a large port intake on the 318 heads, but you won't gain anything, the port is the limiting factor. Sure, the port window can be opened up to 340/360 size, but the gains are probably not worth the cost of a set of head gaskets. That said, there are 2 templates in every 340/360 gasket set.
If your 302 heads have the stock sized valves, just bolt on a Performer, it'll be fine.
There are 4 pretty common intakes for 318 sized ports; the regular Edelbrock Performer or Weiand 8007, both currently in production, and Edelbrock LD4B and Holley Street Dominator, both out of production. The LD4B is a good intake and still popular, a nice used one is worth $100 when you can find one. The factory iron dual plane 4 Bbl intakes were all large port. There was also an iron small port single plane 4 Bbl intake on the 273, and Edelbrock SP2P's are out there used. The last two are worth their weight in scrap and should be avoided.
You could certainly use a large port intake on the 318 heads, but you won't gain anything, the port is the limiting factor. Sure, the port window can be opened up to 340/360 size, but the gains are probably not worth the cost of a set of head gaskets. That said, there are 2 templates in every 340/360 gasket set.
If your 302 heads have the stock sized valves, just bolt on a Performer, it'll be fine.
I believe that even the Edelbrock Performers went to 360 sized ports awhile back. They used to be 318 sized ports, but not anymore.
Edelbrock Streetmasters (also out of production), also have small ports. Single plane intake with small runners for higher velocity and 318 ports.
The 302's were strictly 318 heads. Closed chamber, 318 ports, and 318 sized valves.
Edelbrock Streetmasters (also out of production), also have small ports. Single plane intake with small runners for higher velocity and 318 ports.
The 302's were strictly 318 heads. Closed chamber, 318 ports, and 318 sized valves.
some times that wall ( small intake to large port) can be beneficial in causing a siphon affect for fuel drop out that runs down the manifold and then gets pulled back into the air stream.
I read a article, some years a go on Speed Talk, and read a thread about this. The porter for some race team, claimed that by have a .050 larger intake exit compared to the head entrance gave more torque with no top end loss.
NOTE: Test result my vary.
If i was going to put a smaller port, intake manifold on. I would grind the roof of the intake to match the head.....and leave the rest alone. If you have ever flowed a head with velocity probe. Then you know that's were all the air want to be any ways.:yawinkle:
I read a article, some years a go on Speed Talk, and read a thread about this. The porter for some race team, claimed that by have a .050 larger intake exit compared to the head entrance gave more torque with no top end loss.
NOTE: Test result my vary.
If i was going to put a smaller port, intake manifold on. I would grind the roof of the intake to match the head.....and leave the rest alone. If you have ever flowed a head with velocity probe. Then you know that's were all the air want to be any ways.:yawinkle:
'72Blu....that is what I was looking for. I already have a Performer RPM knock-off intake, not on the engine at this time, and wondered if the port window was equil. Time to save up my pennies for a set of Engine Quest heads......
Bob
Bob
Don't get hung up on port size on a low budget build. Large port intakes ARE better than the old small port/ small runner 273 intake with a small cam and good exhaust. Chrysler did that very thing with the 4bbl 318s in later years, basically a 360 intake on 318 heads.
What are the details on your build? I assume you're building a 360 then?
This is correct. The 308 heads are the same swirl port design as the 302's, but have the larger 360 sized ports. HOWEVER- they are open chamber heads, not closed chamber like the 302's. The set of 308's I had ported for my 340 flow 264 cfm on the intake side at .500", so they're pretty capable heads, pretty much similar to any of the J or X heads with the proper sized valves, just a better exhaust port. The set of 308's I have actually cc'd out to be 65cc's before I had them cleaned up, they ended up at 64cc's. But like the X and J heads I've heard they can run much larger also, I must have gotten lucky.
skrews
Well-Known Member
It was a 318 head only. Edelbrock Performer, Weiand Action Plus, M1 dual plane, Holley Street Dominator, Edelbrock StreetMaster are the best matching intakes. The OEM iron 340 and 360 intakes will also match up decent.
Details of the "build" are sketchy at best. What I have is a late model, roller cam 318 short block on the stand that I want to build for my '65 Valiant. The car will be a sort of combination cruiser/long hauler/pro touring-ish deal so drag racer style performance is not a priority. That being said I still want enough oats to spank the backwards baseball cap, green haired, multi-pierced punk next to me in the 'stang......sort of a "up yours, sonny, you just had your *** waxed by an old fart" deal. I have been thinking, if the block will take a 40-thou over-bore, of dropping in a 4" cast stroker crank for a small bllock 392. That number has some chops in my mind, 390 (Ford and IH number) does not. Keep it pump gas friendly with good heads, flat top pistons, Performer RPM-ish intake, maybe a self learning injection set-up, TTI Headers to my existing 2 1/2" dual Exhaust system, stoutly built low gear set 904/999, with a 2.94 geared 8 3/4 suregrip out back. Option B transmission would be a 5-speed manual, 5 TH gear overdrive, and a 3.23 out back. Commments and/or suggestions welcome here.
The EQ heads will flow right at 250 out of the box and closer to 260 with 2.02 intake valves for just under $1,100.00. Dollar for dollar I would have at least that much in a set of ported 308 heads built along the same order as the EQ's. I'm not saying that the 308 are not a good value providing you are handy with a die grinder....I'm not.
Bob
The EQ heads will flow right at 250 out of the box and closer to 260 with 2.02 intake valves for just under $1,100.00. Dollar for dollar I would have at least that much in a set of ported 308 heads built along the same order as the EQ's. I'm not saying that the 308 are not a good value providing you are handy with a die grinder....I'm not.
Bob
2 Darts
A-body Addicted
Suggest have a mild port, polish, and 3 angle valve job done on 302 heads along with a swap to 360 size valves. On your build up use a 70 or earlier piston which sits a little higher in the bore than the later ones. It's still pump gas friendly. The only OEM manifold that will match properly is the one from the 66-67 273 4 bbl. The others are for the large port heads. IIRC the Performer has bosses for FI that only need to be machined. For cam, I wouldn't recommend anything more than a .500 lift for street use. The .450-.500 range seems best (others will disagree, let them do so and state their case.). Run an OD transmission with a 3.55:1 rear gear. It should let you do about 2K rpm for loafing along at 65 mph.
You could put more heat in the motor and make the car less driveable for your primary uses, but why? Since you "still want enough oats to spank the backwards baseball cap, green haired, multi-pierced punk next to me in the 'stang......sort of a "up yours, sonny, you just had your *** waxed by an old fart" deal."; why not slide a cheater shot of nitrous into your ride? Nobody says you have to have it on all the time or even have the bottle in the car. It's cheap 'n quick and easily un-doable in the event the activity loses its appeal.
If you're going to stroke it, don't bother with the 302's. Even ported and polished they're going to be the restriction on a 392 ci engine. The EQ's would be a much better choice for that, and as you've pointed out they're probably more cost effective too. With a 392 stroker and that kind of flow, you shouldn't have any trouble making 400-450hp even with a fairly mild/moderate cam, so no worries on it being a driver.
3.23's are no big deal even for long haul trips. I have them in my Challenger (318/904) and have no worries cruising at 80 mph, and that's with pretty short tires too (25.7").
3.23's are no big deal even for long haul trips. I have them in my Challenger (318/904) and have no worries cruising at 80 mph, and that's with pretty short tires too (25.7").
Valvebounce
Well-Known Member
Don't forget the Edelbrock LD4B. Guys swear by those manifolds.
2darts....The only issue with the OD transmission (automatic) is getting it installed. Too much cutting on my cherry transmission tunnel/X-member. I know that installing a manual will also involve some cutting but I won't be cutting a X-member. I thought 302 heads already had the 360 sized valves? The engine currently in the car is from an '87 5 TH Avenue along with a lock-up 904 transmission that I assume came from the same donor car. Transmission has been "built", full throttle up-shifts border on brutal and the lock-up feature don't work. Have a builder non lock-up 904 in the barn waiting to be converted to 999 status.
Cam choice looks like a grind I have seen advertised on a couple of crate engines from Indy Cylander Head. I believe it is a MP grind, .470-ish lift at about 216° duration at 0.050 Hydraulic Roller. Should work great with the EQ heads and roughly 9.0-9.5 compression.
Performer Intake currently on the car does not have injecter bosses.
72blu.....currently have an issue with incorrect speedometer readings. I suspect the tire OD and the speedometer drive/driven gears do not match up. When I get the builder transmission done I will get the correct drive/driven gears for a 26" to 27" tire installed. Tire package looks to be a 215/60R-15 up front on a 6" rim and a 235/60R-15 (if it will fit) on a 7" rim. Second pick for the rear would be a 225/70R-15 on the 7" rim. If I run a non overdrive trans I want the tallest tire I can package in a stock wheel well.
Bob
Cam choice looks like a grind I have seen advertised on a couple of crate engines from Indy Cylander Head. I believe it is a MP grind, .470-ish lift at about 216° duration at 0.050 Hydraulic Roller. Should work great with the EQ heads and roughly 9.0-9.5 compression.
Performer Intake currently on the car does not have injecter bosses.
72blu.....currently have an issue with incorrect speedometer readings. I suspect the tire OD and the speedometer drive/driven gears do not match up. When I get the builder transmission done I will get the correct drive/driven gears for a 26" to 27" tire installed. Tire package looks to be a 215/60R-15 up front on a 6" rim and a 235/60R-15 (if it will fit) on a 7" rim. Second pick for the rear would be a 225/70R-15 on the 7" rim. If I run a non overdrive trans I want the tallest tire I can package in a stock wheel well.
Bob
2 Darts
A-body Addicted
I think there is a solution to the OD/tunnel dilemma that does not involve cutting. IIRC it is a custom cross member that bolts in place and uses a stock isolator. It does require shorter drive shaft and a re-set of the pinion angle of the rear axle.
Don't know what car the wheels are going on. 7" wide with a stock offset fit fine on both of my Darts. The '73 4-door has disk brakes (pushing the wheels out a little farther in front) with 205/60-15s on Magnum 500s. The '72 Demon has a disk brake '75 front end under it with 235/60-15s on cop car wheels. Clearance in the back is a little close, but no rubs since installed 3 yrs ago. In the front, the fenders had to be massage a little to keep the tires off of the top of the wheel well opening in spirited driving.
For what it's worth, I tried 255/60-15s under the Demon. The rear springs would rub the sidewall in quick turns. No problems with the fenderwell. Up front, the tires would bounce off of the inner fender going straight ahead over mild to moderate bumps. Other FABO members report no problem with this combination. From my experience, I wouldn't recommend anything larger than a 235/60-15 wheel/tire combination. Right after my test with the 255s, I called Stockton Wheel and asked what their recommendation would be for a stock Duster/Demon with BBP disk brakes using cop car wheels.. It was a 235/60-15.
Don't know what car the wheels are going on. 7" wide with a stock offset fit fine on both of my Darts. The '73 4-door has disk brakes (pushing the wheels out a little farther in front) with 205/60-15s on Magnum 500s. The '72 Demon has a disk brake '75 front end under it with 235/60-15s on cop car wheels. Clearance in the back is a little close, but no rubs since installed 3 yrs ago. In the front, the fenders had to be massage a little to keep the tires off of the top of the wheel well opening in spirited driving.
For what it's worth, I tried 255/60-15s under the Demon. The rear springs would rub the sidewall in quick turns. No problems with the fenderwell. Up front, the tires would bounce off of the inner fender going straight ahead over mild to moderate bumps. Other FABO members report no problem with this combination. From my experience, I wouldn't recommend anything larger than a 235/60-15 wheel/tire combination. Right after my test with the 255s, I called Stockton Wheel and asked what their recommendation would be for a stock Duster/Demon with BBP disk brakes using cop car wheels.. It was a 235/60-15.
Car is a '65 Valiant. Current rolling stock is 215/60R-15 rear and 196/60R-15 front, all rolling on 8" cop rims with 4.5" of back spacing. Figured 235/60's on 7" rims with 4" (maybe 4 1/4") backspacing would do the deal. There is a gain of .7" of section width going from a 215 to a 235. Not sure but am told that the cars are identicle aft of the torsion bar X-member so would assume your and my rear wheel wells are pretty close. And yes, I know the 8" wheels are too wide for the 195's up front and are marginal for the 215's out back.
Bob
Bob
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