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Anyone familiar with sbc?

Audi0

Audi0

Super Member
Bought an extremely modified jeep that has most of 305 sbc there with th350 transmission.

Can anybody give me some advice.

What kind of distributer do I need? The parts store cant give me a clear answer as I only got half of it. I'm assuming something vacuum advance. The msd coil pack is left over from sbc that was here originally.

Not to sure what kind of edlebrock carb I can put in it. I have the gm manifold number how do i look it up to know what will fit? I may need a spacer? Store gave me a run around also.

I can work my way around a stereo and do transistors subs and what not but I'm a little lost here. It should be simple but really need guidance.


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Well, you're gonna need to provide as many specifics as you can here ... Manifold type, compression, camshaft specifics, cylinder head specifics, exhaust specifics, etc. If you don't know, have someone help you that can make these determinations before buying part 1.
 
damacman said:
Well, you're gonna need to provide as many specifics as you can here ... Manifold type, compression, camshaft specifics, cylinder head specifics, exhaust specifics, etc. If you don't know, have someone help you that can make these determinations before buying part 1.
Click to expand...


Engine is an unknown to what it was pulled from so store is hesitant to sell me anything.
It's running v belts instead of serpentine which may be a clue to date it?

-Factory manifold chevy part # 14057055
-Camshaft I'm assuming is factory
-Heads look factory
-8:1 compression?
-Hedman exhaust headers running dual 3 inch pipe
-Custom braided fuel lines
 
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For the distributor all you need are a HEI V8 cap for an external coil (Accel & MSD make external coil adapters for that big cap distributor to have an external coil as it normally had a special one in the cap) , rotor , & plug wires.

I would recommend finding a good used quadrajet carb as it was OEM (It has much smaller pair of primary ports verse the secondary ones) and it will work best and likely your intake manifold is made for one. . It will however need rebuilding and HP makes a good book on rebuilding them. Too bad I wasn't near you as I have rebuilt many.

I t may not cost much more to add a good fuel injection system (unless you get the carb cheap) , with all it's advantages of better MPG, longer engine life, and nicer starting etc. You can use used GM parts to also do the whole job for not a big cost.

OEM- original equipment manufacturer.
 
I agree with big, I’d go with a factory HEI distributor and forget 5hat external coil. I myself wouldn’t bother with a quadrajet either. I’d go with an Edelbrock 1405 or 1406. 600 can carb, direct bolt on. 305’s weren’t a great engine, but in a Zjeep should be a lot of fun. Simple and cheap to work on.
 
That looks like the bottom of an HEI distributor. I recognize the ignition module. It needs a cap and a rotor at least, but not sure what else may be going on there. It may be fairly complete honestly. If it is, I'd run whats there. The HEI dizzys don't drive an external coil, the coil is in the cap and when all is connected you just feed it a key-on + source.

I like Q-jets if the manifold is a spread bore. Those square to straight bore adapters always struck me as stupid from an airflow standpoint. Big into small, small into big, it makes no sense. If its a square bore carb, the Eddy will work fine. If its a 2bbl, that will also work fine.
 
First off the auto store will only have info for a factory built car, that's how they find parts you need. If you can get a close ID of the engine, when ordering parts for it you give the car, year and engine size to them.

Audi0 said:
-Factory manifold chevy part # 14057055
-Camshaft I'm assuming is factory
-Heads look factory
Click to expand...
Look up head casting and manifold numbers, most have an alphanumerical date code as well, that should put you pretty close to year, and might put you on the engine code for HP. You know it's an automatic and that's important for the Distributer as well. You can kinda guess when ordering parts but the store needs you to tell them a factory car.

I don't see this engine as being modded other than small add ons. Most likely pulled from a running donor car and they added exhaust system to fit the jeep. The Distributer also has part numbers and you can find out witch one you have and what cars it was used on, you can order parts for it.

If you don't have a carb, you can go aftermarket and you would get one that fits the needs of the engine and trans. This carb will need to work with the auto trans kick down for shifting, the vacuum distributer for advancing. It will need a little fitting of the throttle linkage and this will be all on you, this carb was never on this motor, and the motor was never in this jeep.
 
So it sounds like you bought a heavily modified Jeep but I'm guessing they kept the modified engine and dropped a 305 in just to sell it? Is this correct?

If just a run of the mill 305, what are your intentions? Just get it running to drive the Jeep around a little with plans on a more substantial engine in the future?

If you're not planning on doing much with this engine, I would go with basic parts. Can you find any numbers on the engine block?
 
There's a tab that extends in front of the pass side head that will have the suffix code stamped on it. That will give you quite a bit of info about what year and what that 305 came out of. The motor will be fine if you just want a cruiser but if you want any kind of power or grunt I'd replace with a 350 or something of the like. ;)
 
The problem with the Edelbrock and other aftermarket carbs is you have to tune (change jets etc) them , and that takes knowledge and equipment. A Quadrajet is an OEM GM carb and if it came off a 305 it will work with no tuning. Otherwise you can have stumbles, poor MPG , stalling etc. !

You don't need any #'s of the block, just get std. HEI internal coil, cap, rotor and wires for a late 70's 305 and don't buy cheap parts. You want a cap with Brass terminals for instance. MSD & Accel make good stuff. The existing external coil could be used to save $ and there is an adapter that goes on a stock HEI cap to run the coil externally from MSD etc. It should be low $ to buy. It was done as the internal coil does have its disadvantages and later GM HEI systems with EFI went that way.
 
A 305 can get pretty good MPG in a lighter vehicle if it's in good shape and tuned right plus torque is good which is handy off road and even in city traffic.
 
FINALLY! a thread where 'sbc' actually means 'small block chevy'. Give me a minute to read and understand and I will toss some part numbers at you
 
ok, I looked you up in my interchange manual yes, I still use paper but most interchange can be found on nastyz28 website (friend of the owner and a lot of the info came from the old Jim Pace dealership info - they were heavy into Gen1 SBC aftermarket)

your intake is a spreadbore design made for a Qjet. any carb that direct bolts ALSO has to be a spread bore.

I would resist any temptation to over carb, on a 305 that wont see 5000rpm 600cfm is more than enough.

why not just order up a reman Qjet?

as for the dizzy, it looks like a vacuum advanced HEI unit. used ones are IMPOSSIBLE to find (I do have a BUICK one however...wont fit) many people make the caps to fit and you can work in the MSD coil. However, HEI is 60kv plus...you NEED to go to large gap plugs (not necc extended reach) but for that I need to know the vintage of the 305. Old or new. probably R45TSX. if you go to less voltage, then std R44T/R45T with mebbe the S

on the drivers side, back of the engine, is a cast pad that tells me what it is block wise. You would want to see '5.0L' and then 'G'..would also need the head castings. if it is a 5 litre g block I expect to see swirl port heads

The stamping pab code helps, assuming an unmolested donor engine, it tells me what it came out of. if this is from pre-80 then its just a toy. 81-84 possibilities, 85+ then its the best you can get.

IIRC the first year of the 305 was 76 and everything was hei so dont try and transplant a points dizzy.

because this does use a vacuum advance, you kinda gotta hook it up properly using a TVS. what carb you goto will dictate my answer for THAT hose routing...
 
personally I'd hope for a fresh water cooled marine engine. Seawater engines tend to rust badly inside. The marine heads and cams were somewhat more performance-oriented than their landlubber equivalents.

from what I can tell, I'd say 1986 or older engine. Valve covers look like the perimeter bolt style.
 
So you maybe don't need a dist. but it's a good idea to pull it and lubricate the bearing for the dist. shaft under the inside plate , and this allows you to check wear on the advance weights (the 2 rusty brown claw like pieces of metal in the middle) You can also check the end play of the dist before you pull it apart. You just have to knock out the roll pin in the gear and save it for reassembly.

Assuming the distributor is properly installed you should mark the exact position of the rotor (after you buy it and the cap) , dist. position as installed at the base so you position exactly as before as rotating it changes the timing.

HEI is a top performing very reliable ignition system and is still recognized as that so it would be a waste of $ to buy new unless it is mechanically worn out.
 
Just going to grab a hei distributor then.
I was told rochester carb but clearly q jet.
The guy I got this from was putting the 305 in as he got it without a motor. Originally it had a 350 with some sort of blower.

Jeep is sort of very *custom* with 37s on it.
Will pull block number later.
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Plan on putting a 350 in it and I have one. Just want to get it running first.
Dont know how a 305 will handle 37s?
 
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You all ready have an HEI dist! Just need the dist cap, rotor and plug wires plus the adapter for an external coil.

Or you can turn it back to stock and so also buy an internal coil and this will be easier to get parts for. Internal coil is probably more expensive than an internal one but should last longer and usually does. I never had one fail!

You have to run a full 12V to to the HEI dist. for the HEI module to run properly also!

The Jeep may have a resistor in it's ignition wiring so check for a full 12V.

For a good spare parts to buy , get the pickup coil , as the wires break internally as it moves with vacuum advance. For reliability maybe replace it!

A spare high quality HEI module is also good have too.

Yes you have the Rochester Quadrajet 4 barrel carb by it's size and green lever hooked to the linkage.

Rochester also built 2 barrel carbs (didn't have a name) which were used on the SBC and other GM engines.

The Quadrajet was also found on all other GM engines back in the day.

Really good Info on HEI dist. that should help!

https://www.gmcmi.com/wp-content/uploads/2014/05/HEI-Distributors.pdf
 
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May handle 37's if the axle gearing is right, but will rev higher on the highway!

305 has the same fairly long stroke of 3.48" as the 350 so it should pull good.
 
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