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New 300 build... questions

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Ctmarto
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New 300 build... questions

Post #1 by Ctmarto » Tue Mar 24, 2020 5:11 pm

Hi I’m new to the forum and am currently swapping my old 300 for a new 300 I bought. It’s bored .30 over has a bigger cam and some head work. It came with a offy 4 barrel intake and a 2.5 single exhaust manifold from a larger hd truck. My question is what 4 barrel do I run as it didn’t come with one. It’s a 78 300 going into my 85 flareside. I heard that I might need a new distributor and that my 85 distributor will not work with the 4barrel. Thanks for the help, I’d like to keep it kind of cheap because I’m only 16 and just finished the body work on the truck as well as some new paint. Thanks !!

pmuller9
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Location: Columbus, Indiana

Re: New 300 build... questions

Post #2 by pmuller9 » Tue Mar 24, 2020 7:22 pm

Welcome to the forum.
You will get plenty of help here.

There is the Offenhauser "C" intake and the Offenhauser "Dual Port" intake.
Which one do you have?

Do you happen to know which cam was installed?

BigBlue94
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Location: Hoyt, Kansas

Re: New 300 build... questions

Post #3 by BigBlue94 » Tue Mar 24, 2020 7:32 pm

If the exhaust manifold exits straight down and has 3 collector bolts, it's the famed HD manifold from a heavy truck. If it has 2 bolts and the exit curves slightly back, it's the standard log manifold. The HD truck manifold is excellent.

For an 85, you'll need to completely rework the ignition. You have three basic methods, with a couple more tossed in.
-HEI, this is a distributor with ignition control built in.
-Duraspark II, this is the system prior to the 84+ feedback ignition. You need the distributor, silver ignition box, and the harness to plug into yours.
-Points and Condenser, with or without a pertronix kit. This is the method used prior to the DSII. It's simple, but not as efficient as the prior two.

There are other ways, but those are the most common. You can also skip all that and run an aftermarket EFI system, but that may be out of your price range.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

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THE FRENCHTOWN FLYER
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Re: New 300 build... questions

Post #4 by THE FRENCHTOWN FLYER » Tue Mar 24, 2020 7:56 pm

Most 4V carbs from 390 cfm to 600 cfm can work well on a 300. Use one with vacuum secondaries - not a double pumper or mechanical secondary.

Welcome to the forum - you just discovered the best Ford six forum on the planet.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

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68Flareside240
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Re: New 300 build... questions

Post #5 by 68Flareside240 » Tue Mar 24, 2020 11:16 pm

Welcome! You’re about to be the coolest 16 year old in the parking lot. Great folks here who are an incredible wealth of knowledge. Enjoy and best of luck with the swap.

Ctmarto
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Re: New 300 build... questions

Post #6 by Ctmarto » Wed Mar 25, 2020 12:35 pm

Thanks everyone for the help, I do have the famed hd manifold and I have a dual port offy intake. I will update the forum as I do the swap!! One more question... I currently have that 4 speed with the granny first I want to swap to a zf 5 speed... is it worth it or should I keep the 4 speed? My truck does terrible on the highway and it has 3.07 gears in it... thanks!
Last edited by Ctmarto on Wed Mar 25, 2020 2:00 pm, edited 1 time in total.

Ctmarto
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Re: New 300 build... questions

Post #7 by Ctmarto » Wed Mar 25, 2020 12:40 pm

pmuller9 wrote:Welcome to the forum.
You will get plenty of help here.

There is the Offenhauser "C" intake and the Offenhauser "Dual Port" intake.
Which one do you have?

Do you happen to know which cam was installed?



The cam is a 274 lift erson PBR cam. I have the dual port intake

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68Flareside240
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Re: New 300 build... questions

Post #8 by 68Flareside240 » Wed Mar 25, 2020 5:02 pm

I assume you mean 274 duration. Do you have the model # of the Erson cam?. The 4 speed granny low is a truck trans and made for low end pulling. I’ve got it in my 77 4x4 and I never use it. Run it essentially as a three speed.

sdiesel
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Re: New 300 build... questions

Post #9 by sdiesel » Thu Mar 26, 2020 12:43 am

I sure wish someone, would use a well prepared quadrajet carb on a 300....
I've been intending to but u know. I don't need it with a Fish carb, I just don't.
But a q jet should deliver astounding performance on our engines

Furthermore the ZF, is an astonishing upgrade.
I always do it with the 300.
The 435 is really lovely under 55 mph.
The zf really stands out above 55.
The zf will accept any Ford transfer case, but, may I suggest a later chain drive model?
A 1345 1356, or equilivant?
U will snap the rear housing with anything bigger heavier. Support of the front drive output is highly recommended along with a torque strap on the engine to prevent too much rocking.
A good t case should cost about 200.00 a BW4407 u will never break but they are heavy on the output side and will require support to avoid cracking the Transmission case.
Cases crack on top at the webbing at the 12 oclck position , just as the case shape drops down from the mating flange to the " tube" where the t case mounts.
The ZF likes a lot of clean atf.
There are issues with comparability of fluids so be vigilant as to what u use.
Overfill by a
Quart will keep ur main input bearing lubed. I fill through the gear shift housing.
Put a new throw out bearing from Ford in b4 install.

I have a small pattern Transmission somewhere back home.

Install the firewall support plate when u do the ZF. U. Can get them from bronco graveyard or terripin engineering it's the same product. A zf with clutch master will tear ur firewall right up.
Sometimes I hate Ford but what can u do? Like their headlight switches Ford knew they had weak firewalls but screwed the consumer and did nothing about it
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

BigBlue94
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Location: Hoyt, Kansas

Re: New 300 build... questions

Post #10 by BigBlue94 » Thu Mar 26, 2020 10:45 am

sdiesel wrote:I sure wish someone, would use a well prepared quadrajet carb on a 300....
I've been intending to but u know. I don't need it with a Fish carb, I just don't.
But a q jet should deliver astounding performance on our engines

Furthermore the ZF, is an astonishing upgrade.
I always do it with the 300.
The 435 is really lovely under 55 mph.
The zf really stands out above 55.
The zf will accept any Ford transfer case, but, may I suggest a later chain drive model?
A 1345 1356, or equilivant?
U will snap the rear housing with anything bigger heavier. Support of the front drive output is highly recommended along with a torque strap on the engine to prevent too much rocking.
A good t case should cost about 200.00 a BW4407 u will never break but they are heavy on the output side and will require support to avoid cracking the Transmission case.
Cases crack on top at the webbing at the 12 oclck position , just as the case shape drops down from the mating flange to the " tube" where the t case mounts.
The ZF likes a lot of clean atf.
There are issues with comparability of fluids so be vigilant as to what u use.
Overfill by a
Quart will keep ur main input bearing lubed. I fill through the gear shift housing.
Put a new throw out bearing from Ford in b4 install.

I have a small pattern Transmission somewhere back home.

Install the firewall support plate when u do the ZF. U. Can get them from bronco graveyard or terripin engineering it's the same product. A zf with clutch master will tear ur firewall right up.
Sometimes I hate Ford but what can u do? Like their headlight switches Ford knew they had weak firewalls but screwed the consumer and did nothing about it


AbandonedBronco ran a Qjet for a while.

Aye on the BW4407. That thing is a monster of a chain drive case. It snapped both upper adapter mounting points on my 96 C6. The 1356 would be the best option. The NV271/273 is great too, but again, too heavy without bracing.

OP- To swap a zf5 in, you'll need the transmission crossmember and braces and the trans tunnel cover for a 5speed. Then you get to have fun with transfer case linkages. The np208 shifter, as you know, comes out of the tunnel cover. The zf5 was only mated to BW cases, and those years all had the shifter come out to the left of the trans tunnel. AbandonedBronco did this swap, and has a thread covering it over on fullsizebronco.com.

If you swap your transfer case out for a newer one, you'll have to get some way for the speedometer to work, as it gets its reading from the transfer case. The later BW1356 equipped trucks had a speed sensor in the rear diff.

Your current clutch and flywheel would work, but I'd get new while it's all apart.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

sdiesel
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Joined: Fri Jan 06, 2012 12:33 am
Location: NW Oregon,Buxton currently

Re: New 300 build... questions

Post #11 by sdiesel » Thu Mar 26, 2020 9:07 pm

Oh yes I fergot bout crossmembers.
What lovely fun.
Seems Ford made different members for every model and every year differently.
I do recall having an exciting time finding the proper member, as my tonner was automatic and none of the holes line up ,, there is front d line issues, and o joy what fun.
Stupid Ford fun. I cannot recall now how that story ends but I must have found one that works.
Oh and don't be tempted to " be bada**" with a np205 gear drive like I did. Hours and days planning and fabbbing and , guess what ? It's too short on the front output thus ur drive shaft runs at a compound angle
THAT I do remember. It's coming out o there.
...someday I believe I will install a Rubicon Jeep t case with 4.10 low. That will aid enormously my six to move around a 9000 pound rig
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

pmuller9
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Posts: 3719
Joined: Tue Aug 06, 2013 12:33 am
Location: Columbus, Indiana

Re: New 300 build... questions

Post #12 by pmuller9 » Thu Mar 26, 2020 10:14 pm

Ctmarto wrote: I heard that I might need a new distributor and that my 85 distributor will not work with the 4barrel. Thanks for the help, I’d like to keep it kind of cheap because I’m only 16 and just finished the body work on the truck as well as some new paint. Thanks !!

A low cost ignition system would be to use a DS2 distributor with a GM 4 pin module.
You can use it with the coil you have now.

You are looking for a 450 to 500 cfm carburetor with vacuum secondaries.

I would recommend either the QuickFuel SL-450-VS Slayer
Or the Summit SUM-M08500VS 500 cfm carburetor.

sdiesel
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Joined: Fri Jan 06, 2012 12:33 am
Location: NW Oregon,Buxton currently

Re: New 300 build... questions

Post #13 by sdiesel » Fri Mar 27, 2020 11:46 pm

The 1356 t case is almost ideal.
I abused it in my tonner for 100k and the truck started out in Canadian oil fields she never had a chance, but the 1356 lives yet in a pile of parts on a cart waiting for one silly spring clip .
The tonners had PTO plates too, some of them did anyway
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

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