454 & drivetrain q's

[magnethead]

I got a few questions bout our engine-

Who made the carb? All I know is that it's a stock replacement (or hell, might even be the stocker... ) quadrajet that's been rebuilt MAYBE once (not sure if we've rebuilt it or not). I'm assuming it's either a GM or rochester (sp?). And what CFM is it, 650 or 750? Or how can I tell (the serial number i think, which is where)?

What form of choke does it have? Theres no manual choke lever, so I assume it's an electric choke?

What size cylinder heads (cc's) does it have, and what compression ratio? Iron heads I assume, not aluminum?

Has anybody ever swapped the boat anchor for an aluminum intake? What changes and effects had to be made and resulted? Any difference in cold/hot weather starting or fuel mileage? How much does it normally cost? Or how can i tell if it's been swapped already?

How long is it normally before a clean-up overbore is needed? I don't think it needs it yet, but then again, theres no hundred thousands space on the odometer, so we really don't know how miles are on it.

Did the '77 454 have a smog system on it at any one time? Theres no evidence of one ever being on ours, but i'm not 100% the previous owner deleted it.

How long is it before a TH400 normally starts getting wore out? Again, we don't know how many miles are on it, but it has a trans cooler and has pulled a race trailer for 2/3 of it's life, so i dont know what it might lok like. I think we've pulled the trans oil pan only once or twice.

What convertor does it have, and is it a locking version?

How long will it be before the rear gears (4.10's in a D70) start wearing out? We acidentally ran it for 2 months without ANY lube in it (it was boned dry), and replaced a faulty pinion bearing/seal to fix it. And is it straight cut or new style (angled teeth)? It has an open diff (we've found that out the hard way).

What has to be done to service the rear drums? It's a dually, so the half-shafts have to come out, don't they?

What fuel mileage difference has been noticed by those who switched from the mehanical fan to an electric one (or two)?

Where can a replacement battery holder be attained, other than a junk yard? A bunjee cord on the brink of breakage is all that's holding it in.

It has stock mufflers- what effects would newer mufflers make?

Here's a couple pics if you forget what everything looks like. It has hydroboost and hedman headers.












^^has increments a few hundred more since that pic^^

[magnethead]

sorry bout # of pics..

[stepside454]

damn thats alot of questions,
The carb should be a Rochester the CFM is 795 if I recall correctly.
now some of these questions you should be able to figure out yourself if you look a little & maybe do a little self research. Do you see a wire going to the choke ? no ? well cant be electric with out an electrical source.
heads are cast iron of course, compression ration about 7.8:1.
How will an intake change effect performance ? under 4500 RPMs probably no change at all (this is one of those do a little research yourself things)
How long before an overbore is needed? depends on how it was used & abused. 77 454 would have only had PVC I believe...I know thats all my 76 has.
How long well a T400 last ? depends on how it was used & abused. it would not be a lock up convertor.
How long well the rear end last ?see above answer to how long tranny & cylinders last.
Servicing rear drums...Id get a service manual (self research ).
Fuel mileage with electric fans....I dont think youd notice much gain over a good clutch fan.
relpacement battery holders are avalaible from Chevy Duty & LMC Truck.
stock mufflers vs, newer mufflers....well, are the mufflers bad ? what kind of differance how ? noise ? mpg ? performance ? newer mufflers as in newer replacement ? or newer performance ?

[magnethead]

Originally Posted by stepside454

damn thats alot of questions,
The carb should be a Rochester the CFM is 795 if I recall correctly.

I figured so..anyone wanna backup the CFM?

Do you see a wire going to the choke ? no ? well cant be electric with out an electrical source.

Then explain this statement made....I'm not sure what it has, as 77 and 78 is basically the same group...

(posted by 60-66 nut): none of the 78's I've seen came with electric choke, only the manifold heat choke.

heads are cast iron of course, compression ration about 7.8:1.

Thanks figured that....wasn't sure on the compression..dang thats low.

How will an intake change effect performance ? under 4500 RPMs probably no change at all (this is one of those do a little research yourself things)

OK

How long before an overbore is needed? depends on how it was used & abused. 77 454 would have only had PVC I believe...I know thats all my 76 has.

PVC??? Explain?

How long well a T400 last ? depends on how it was used & abused. it would not be a lock up convertor.

So THAT'S where the mileage left us at...

How long well the rear end last ?see above answer to how long tranny & cylinders last.

suits me

Servicing rear drums...Id get a service manual (self research ).

Sounds like a fun project...and pricey...

Fuel mileage with electric fans....I dont think youd notice much gain over a good clutch fan.

I've heard otherwise, but OK

relpacement battery holders are avalaible from Chevy Duty & LMC Truck.

Thanks

stock mufflers vs, newer mufflers....well, are the mufflers bad ? what kind of differance how ? noise ? mpg ? performance ? newer mufflers as in newer replacement ? or newer performance ?

Well thats the problem- we don't know how clogged they may be......

[magnethead]

These are all that's left (rephrased from partial answers)..


What CFM is the carb? want somebody to back it up...

I want somebody to backup whichever choke style it has...

What size cylinder heads (cc's) does it have?

Did the '77 454 have a smog system on it at any one time? Theres no evidence of one ever being on ours, but i'm not 100% the previous owner deleted it.

[RockHQ]

Your cheapest mileage gains will come from cutting weight down. Remove any and all things not absolutely needed or functioning from the engine compartment, front clip, cab and bed. Next, drill holes to the radiator support, fender supports, inner door skins, brackets and so on. Replace inner bedsides with aluminium sheets. Replace steel parts with aluminium.

You'll be surprised how much "extra" weight can be taken off without compromising the trucks strength and practicality. No, it won't be as comfortable or quiet but it is after all a truck, not a luxury sedan. It all comes down to how far you are willing to go.

[edit]

Basically, quadrajet main bodies come in two versions, the bigger one flows around 800cfm due to it's bigger primary barrels, whilst the smaller one flows around 750cfm. FWIW, your smog era 454 would work well with either one as long as the carb is properly tuned.

[76HighSierra]

Originally Posted by magnethead

These are all that's left (rephrased from partial answers)..


What CFM is the carb? want somebody to back it up...

I want somebody to backup whichever choke style it has...

What size cylinder heads (cc's) does it have?

Did the '77 454 have a smog system on it at any one time? Theres no evidence of one ever being on ours, but i'm not 100% the previous owner deleted it.

I believe the 795cfm quoted is correct. If your truck has the Rochester 4MV (like it should), it will have what is called a divorced choke. A rod running from a heating element on the intake, to your carb. If the carb is an M4MC (possible but not likely, as most 454's in trucks of that vintage came with the 4MV), it will have a hot air choke. It likely has the "781" casting heads. These have 118.cc chambers , with 256cc intake runners and 114cc exhaust runners (according to Mortec). It may have another casting, though, and the only way to be certain is to pull your valve covers and check. Only the California emmision models had anything but a PCV (Federal models were very simple). Hope this helps.

[magnethead]

Thanks!!