Was there ever a LA 318 4 barrel intake from the factory? Is so, what was the casting number?

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Great question. I don’t think there was. Just like there was never a 2bbl 340 that came from the factory.

Yes, mid 80s Diplomats cop car motors
Thats the only one I know of

Yes, 1976 and later I believe
Mopar used some Quadra Jet carbs also in the mid 1970s, 1976 to maybe 1982 but I'm not sure if they had different intake manifolds or not than the same year Thermoquad carb. motors used

They were available. Not sure exactly what years. I know for sure 1980 aspens with California emissions had them. I know there were others possibly on some trucks. All the factory ones I recall would be spread bore for a thermoquad or quadrajet card. Remember most la318 heads have smaller ports. So you most likely would want 340 or 360 heads.

Was the intake port size 318 or 360 size? Or was a 360 intake used on the 318 heads????

The intake ports were larger on the 4 barrel versions. So the factory 318 engines with 4 barrel carbs would use the larger ported heads. I believe the heads were the same between the 318 and 360 4 barrel designated engines.

I had an 84 Grand Fury police sedan. It had 318 with Quadrajet carb, 360 intake and heads on it from the factory.

318 4bbl intake? yes and no.

The factory put 360 heads and 360 4bbl intakes on 318's, so I guess technically it's a 360 4bbl intake but that's mostly hair splitting. I've put the 360 4ll intake on a normal 2bbl 318 and while some will talk about intake revision due to port size mismatch it's never been anything other than an improvement on a street car.

As for no 2bbl 260's, that's not true at all.

Think he said "no 340 2-bbls."

I need a new set of eyes apparently

How about three two barrels? Does that count

I thought that there was a 1975 Fury based Road Runner that had a 170 HP 318 4 barrel. I know that the Diplomat and Gran Fury police cars of the 80s had 318 4 barrel plants.

I also thought the 73-4 Road Runner with it's standard 318 had a 4 bbl.

1978 was first year, a 360 intake on 318 heads. IIRC, it was a police car only option that year.

My Dad had both 73 and 74 Road Runner's with 318's brand new. They were both 2 barrel, dual exhaust. I ran the 73 at Milan Dragway. 15.90.
Doug

Okie dokie. Good to know

I have a 1987 E58 4 bbl quadajet 360 from a 87 PU truck.

When Chrysler put 4-bbl mflds onto their 318s, the intake mflds were from 360s ... and they also installed 360 cylinder heads which had the matching larger intake ports for the 360 4bbl intake... they were smart to do that.

For the 72-74 (??) road runners, that had the 318 in them . . . exhaust manifolds were port sized for 360 heads . . . they were even cast with "318 - RR" on them . . . note the right hand one had no heat riser drilled . . . used these on the 360 in my Sport Satellite . . .

Why do you have RONA on a 5 gallon bucket ?

RONA was Canadian hardware chain bought up by Lowes.

Beat me too it lol.77-79 Volare’s and Aspens in stock are very competitive with the 318-4, same heads and intake as the 360

I think most of the confusion comes from early and late model engines.

IMHO no 318 came with a small port 4v intake, they all got 360 heads 1.88/1.60 vales and the large port 360 4v intake which is a spredbore flange.

yes you can use a 360 4v intake on small port heads I just say result vary but is always an improvement. factory 4v 318s are the best.

what I think many misunderstand on this is the small port head which was 273 & hipo 273 first then1967 LA318 2v head. mopar did have a 4v small port intake. the IIRC 65 yr was an odd intake bolt angle. they were small port/low rise/single plane intake with a 4-hole square flange. 2v 273 had a 2v intake and the runners all looked similar in X shape/low rise single plane compared to later duel plane runner layouts.

so IMHO a early 273 4v intake is what is needed to best fit the late model small port 318 heads.

this is why I run a 273 4v intake on my small port 318 heads

or run a HOLEY STREET DOMINATOR that has small ports and runner layout like the 273 hipo

or a edelbrock LD4B with small runners/port size FYI which is a reverse copy of the larger edelbrock LD340

35 yrs of wrenching and swapping 2v to 4v on daily drivers I have found the smaller port intakes work much better with small ports heads but are just maxing the flow of the small vales.

when using the 360 heads 188/160 valves large port intake it just has more breathing capabilitys and makes for a more fun street engine.

but I have had good results with a small port intake going on a large port head. which this will also work and will help keep port velocity up going into larger head/valve ports.

I have had a couple LA318s 2v small valve/port heads running a stock 273hipo solid lift cam/rockers(.500 lift) with a 273 low rise single plane intake passing it off as a 273 in a 68 dart 4 speed 4.10 SG 26" tire.

what made it impressive to me was it was a high reving screamer on the streets for daily driving and mucho fun to drive.

"Gran" Fury. Sorry, I had to.

(IMHO no 318 came with a small port 4v intake, they all got 360 heads 1.88/1.60 vales and the large port 360 4v intake which is a spredbore flange.)
Correct

I just sold a 4bbl spread bore intake with a 1980 casting date that had small ports. I do not have the casting number, but I remember looking up the numbers and it said 360-318 engines. I too thought that all small block spread bore intakes had large ports, but this is not the case for some early 80's small block engines. I wish I had written down the casting number because I thought it was strange that they used a small port intake on a 360. When I bought the manifold, I did so because I wanted to use it on a 273 I had. I just sold the 273 and intake 3 days ago.

they do make the best 318s to transplant into something else. they are rated @177HP over the 3182v @150HP

IIRC the one I got from you Larry was 89 318 4v from a Gran Fury. that's what is in my 85 stepside at the moment. swapped it over to a whiplash roller cam/lifters, rpm air-gap 625cfm afb, headers 727-3.23 with .2.5 duels & muffs it is a little screamer now. very fun to drive in traffic.

Yes Mike, it was an '88 Gran Fury AHB "S" Code VIN and "ELE" fender tag so factory HD 318 with 360 heads, intake and exhaust manifolds.

I have always heard that putting 360 heads on a 318 to run a 4bbl intake resulted in a compression ratio drop due to the difference in the 318 and 360 head chamber size.

Some even claim that the compression ratio drop nearly negates the advantage of the 4bbl carb.

Is this correct? And did Mopar address that when producing the 318 4bbl?

No 4-bbl 318LA, how comes, but yes in a Poly 318ci, classed as a lowPO motor for some strange reason?

Then you can get an 8-BBL for a 318ci Poly lowPO motor and an 8-BBL for a piddly 273ci...

True, simple look at the FSM will bear that out.



I think the compression drop helped meet the NOX emissions requirement because I seem to recall there was a time in CA where you could not get a 2bbl 318 in the M bodies at least. Hard to find a good source of info but it seems the factory 318 4bbl had about 255 more HP and 5 more ft/lbs of torque. But I'd like to see the dyno sheets since torque is so close HP has to be too. Might be one of those we picked a number rather than max numbers.



Address what? Other than the intake, carb and head swap there rest of the 318 was pretty much the same as any other 318. Cam was the same broomstick not even sure if the ignition curve was optimized for performance rather than fuel economy or emissions as by then it was pretty much all lean burn and computer controlled. Of course my experience was towards the end of the 318 4bbl time frame not the beginning.

I know the compression on the 318-2 in the 80's was 9.0 and the 318-4 was 8.4. I've owned both and I know the seat in the pants difference is HUGE. Maybe a lot of it is the sound from the Thermoquad through '84 then Quadrajet, but the S code ELE's sure feel much stronger. And that's back when Chrysler added copious amounts of beefed up internals to their Police engines, unlike today where they just add external coolers.

Factory 2.9 rear gears, no more cats, air pump gone and heads plugged, and very easily break the wheels loose. I know, big deal, but it makes it more fun.

The casting # on the intake I had was 4173915, casting date was 3-26-81. Says they were used on 78-80 360's and 78-83 318 4bbl's. This manifold has 7/8 x 2 inch ports while most of the other spread bore intakes had 1 x 2 3/16 ports. Three years ago I went through trying to ID this manifold on here.

it was 85 up 318s got a comp bump to the 9.0 to 1 with a taller piston comp height and the closed swirl port chamber #302 heads. from the few police 85-up 4v318 engines I owned, I found they had the 9.0 to 1 piston comp height but the open chamber 360 heads drops it down almost a full point of comp. what is really different is the cams the 4v 318 use to maximize the 360 head flow.

so if you take a 2v 318 with the #302 heads 9.0 to 1 comp ratio and drop on a set of 360 heads/intake it does 2 things. 1 it drop comp ratio, 2 it still has a whimpy 2v cam with less than .400" lift

THIS is why most people say it kills effort. and say it sucks.

IMHO this is why a whiplash cam does so well in a low comp engine and works well in a street engine.

the early intake closing build cyl pressure so it does not kill off torque.

the larger valves/runners and high lift flows more in the upper rpm range. these 2 things alone make up any loss from the swap in over all performance you really feel in the seat of the pants in traffic.

example... if a stock 360 head max flow is around .450 lift any cam with more than a .450 lift is a waste as you can not get the max flow of cam due to head restriction.

so the right cam is KEY to swapping 360 heads/intake onto a lopo 318 remember though it is easy to over cam a 318 as well. so pick a high lift & short Dur @ .050 cam like the whiplash line of cams.

look at a 340 cam sheet .420/.443 lift range with x heads. so lift is right around max flow of the heads. THEN add some cubic inch & 10.5 comp with a 6-pac 4 speed 3.91sg and it becomes a high rpm legend on the streets. yes I remember in 68 when 340 A-bodys ruled the streets.

another reason I have always used a 340 cam in most 318 with the smaller heads. makes a fun daily driver. but I am hooked on the whiplash roller cams now and cant wait to run my 5.9 magnum whiplash roller cam in my home ported, back cut, #302 heads on a backward piston 318 next.

Yea, folks are really confused over this stuff.

This guy says, pay me $1500 for my cop car intake and carb.

https://www.ebay.com/itm/LAST-CALL-AS-I-WILL-NOT-RELIST-1978-79-LIL-RED-EXPRESS-COP-CAR-E58-INTAKE-CARB/173844514001?hash=item2879f0c4d1:g:skIAAOSwb2hcktUn


But then here is the intake with the PN mentioned above for a semi fair $200.

https://www.ebay.com/itm/80-Dodge-St-Regis-Plymouth-Fury-360-Police-Manifold-4173915-3-Date-Code-5-2-80/174543816769?epid=6037070795&hash=item28a39f4841:g:8rwAAOSwCxtfyMhK

here : https://www.ebay.com/itm/LAST-CALL-...SS-COP-CAR-E58-INTAKE-CARB/173844514001?

and here :
https://www.ebay.com/itm/80-Dodge-S...4173915-3-Date-Code-5-2-80/174543816769?

i don't have the numbers in front of me but it seems like that $1,500 ebay guy is banking on his parts being from a lil red express.

Stock cam in a 2bbl or 4bbl 318 was the same during the flat tappet era. The stock cam in a 360 was barely over .400" lift anyway. Even when they went roller the cam specs didn't really change much between the roller 2bbl's and the flat tappet 4bbl 318's. A few more degrees intake duration was about it. Lift and exhaust duration were the same but your point about the 340 cam is well taken. For the money it's probably the best option out there. basically any 318 needs a different cam from stock to wake it up.

Heck I bought the whole truck for $1500

my understanding is you are correct on the mass of 318s but a police pursuit engine had different specs with upgraded internals. such as full groove main bearings/ HV oil pump, full time oiling to rockers with #2 & #4 cam bearing having a full groove, sodium filled exhaust vales, double roller t-chain plus the oil/trans/PS coolers and 3 core rad-HD 5/8" shaft 8 vain wp, 7 blade thermo-clutch fans

on the cam bearings I have not been able to source a new set as of yet and have only found them in a police code engine. the engine I got from Larry confirms this as it was a roller block with a flat tappet cam which is correct for the 89 4v 318 police code engine. IIRC the cam had .410 lift on intake but defiantly not a mass 318 flat tappet

I printed out some info on head casting #s and engine specs. it shows this 89 4v police engine as having 177 HP @ 4800 rpm where a normal 318 was 150Hp @ 4800 also showed that it was pre-magnum open chamber swirl port 360 heads with #308 castings and they ones I have on my engine. ( I forget the other head casting #s Imwill recheck them)

that may also be where the slightly smaller measurement of the 360 port size comes from with the later model 360 swirl port open chamber heads. as the 915 intake talked about earlier was on the 89 police engine I have. gave that intake to member (locomotion)

so the early non emission 360 heads 72-84? have the larger port opening and are not a swirl port chamber and the late model #308 heads where labeled as swirl port chambers along with the #302 head introduction in 85. 360 went roller cam in 89-91 so that may be when #308 head came out? but either way the #308 pre-mag head is the best one to find but prone to cracks.

With the 340 cam the 318 IS a low comp 340 just 22 less cubes

I agree> a 318 will rev and do what a 340 does if geared right. if you have a 340/3.55 gear = 318/4.11 gear but that is after a cam/head/intake/carb/exhaust swap LOL!

.410" lift is the spec for a 360 cam. Might be misremembering? Or someone swapped in a 360 cam? I have a stock 360 roller cam I had kicked around putting into my 87 318, but I think I'll just get a newer design cam with more lift rather than fool with the stock 360 cam.





Well, 4bbl vs 2bbl would likely be the difference between the HP numbers.




I think you may be right on the port size difference.

Wrong. 78-83 318 4bbl engines got the 4173915 intakes with 1x2 inch runners. I just sold the one I had. 78-80 360's had them as well.

well I just removed one from my 89 police engine replacing it with the RPM Air-Gap intake. this engine was untouched from Larry's ex police car. I don't recall the first digits but last 3 were indeed 915

yes LOL! 2v vs 4v ratings kinda like gross and net ratings but really apples to oranges.

78-83 used a thermobog and 85-up 3184v used a q-jet till the end of pre-mag engines so 78-83 360 heads would be the non swirl port open chamber heads (maybe port size change in 78 and stayed 2" even when going to swirl port technology? that would keep a 915 intake. only difference I see on the 2 different intakes, is how the choke heat well is shaped/milled or molded away on the later feed back q-jet carbs vs thermobog intakes that use it.

but biggest thing I learned wrenching is never say never with mopar, they used up a lot of left over odd & end stuff piecing things together just before going to the magnum engine across the board.

when in doubt measure again.

What was the casting date on it? That would settle the issue.

I have the original 79 lil red express truck intake (360) and I’ll check the numbers tonite. And measure too

Ok got pics if needed. Cast date, 2/6/79 360 intake # 4100340-2. Cast date 10/1/71 340 # 3614025-1. Both ports are the same size.

The casting date on my manifold was 3-26-81. Casting # 4173915. I was replying to Gtxxjon who stated that they never made a small port 4bbl intake for LA 318. I went through this crap right here on this forum 3 years ago trying to figure out what I had. I had never seen a small port spread bore intake before, so I looked up the casting number info and it clearly stated that the intake in question was used on 360's from 78-80 and 318's from 78-83. I had always thought that big port intakes were used on Lil Reds and E58 engines.

The intake I showed is off my 79 lil red express, original numbers matching engine

Chrysler of México assembled on 68/70 period a 318 with 4bbls intakes, 340 camshaft and HiPo pistons made specifically for this engine and used on their Dart GTS versión ( yes, 70 too ). Advertised as a 270 HP engine. Can't tell which heads or some other details. These engines were later exported to Venezuela and Chrysler of Venezuela installed them on 70 Coronets and 71/72 Charger assembled locally, all badged as R/Ts.



On lates 70s USA offered 318 with 4bbls on M, F and B bodies for Cali. Not just police cars.

I think the smaller 2" port size may also be due to push rod hole size. it got bigger for roller cam & shorter PRs. and this also made the dogleg in the intake runner a little more of a restriction in flow.

4323354 on my ‘89 Diplomat Police “ELE”

Attempted to rotate pic