1973 Chevy 3/4 454 - 496 build + more

[munger]

what was your gas mileage stock

[RPOZ11]

I'd guess at anywheres between 8-12 MPG ; depending on how hard my driving was.

[RPOZ11]

Originally Posted by RPOZ11

Here are 3 simple shots of the Thorley Tri-Y's being increased to 3" collectors.

I am going to have these "Jet Hot" type coated to look new again.

Looking at a 3" or a 2-1/2" pipe system with either an H or an X system incorporated into it.

Small steps.

Here is a quick pic of these being done.

Will post more pics later...

[RPOZ11]

2-27-2010 Update :

Got a problem with the headers.

Took a really close look at the finished results last week and found that the "collector rings" WARPED from the heating processes when these were replated as seen above.

Not sure why this happened but we had to take them back after fixing them back to straight.

Very Odd circumstance!

So, as I am awaiting the return of these, I took the 73 in to install the 3:21 ring and pinion gears and install the Eaton Limited Slip Posi unit that I bought.

Using new carrier bearings etc on the install.

The axle bearings turned out to be OK after inspection.

We get the truck back next weekend.

3-6-2010 update:
Supplier sent the wrong POSI UNIT!
1 more week until I get her back to do the exhaust!
( Why is my luck based upon delays??? )

[RPOZ11]

Got my truck back last night.

Everything seemed OK, until........

I noticed this :







UUghhhhh

[89muscletruck]

ouch!

[RPOZ11]

496 is Finally completed ; minus distributor, carb and new small parts.

The push rods arrived in the wrong length so we went bought another set.

Going to rebuild a later model Quadrajet and include an electric choke in the vacuum pod's place.
Probably bush the throttle shafts, tweak it up to handle the larger cubic inches, recolor it and adjust it after breakin.

Small list of stuff to target now:
Radiator
New motor mounts
Belts
Aluminum water pump
Hoses
Starter
Temp Gauges
Misc other things


Hope we start the R & R in 3 weeks.

[RPOZ11]

Picked up my motor yesterday.

(valve covers are on backwards only for the purpose of sealing it up and for transport-FYI)

Man, this is getting expensive!

Dropped it off over at my friend's shop, where we will be doing the swap at.

Next door they have a DYNO.

It was optioned to me to break this thing in on the DYNO and tweak it for power.

Gotta think about this.

The camshaft was off on the dial in. We ended up advancing it 3*. The duration was bumped up a little on this cam to adjust for the extra cubic inches.

Took a core QuadraJet with the electronic choke in for rebuild. Do it up all new, bush the shafts, etc etc.

Also took in a DAVIS "DUI" HEI I had that was used on a prior 454 I had and will reset the advance to match up with this 496. I think that one was originally set up a 22* @ 3400 RPM's.

So, next I have to steal some pulley's, A/C brackets, and more form a core 73 454 I have lying over here, and start assembling the front of the motor.

Im just fortunate to have a spare motor and parts truck to take from while I still drive the truck before we start the swap.

Gonna purchase some Urethane motor/trans mounts.

Slow movin' but progress is being made.

[RPOZ11]

Originally Posted by 77BBGMC

I'm going to be building a stroked BBC as well. I have the block and a good set of 781 heads, now I'm in the process of saving some $$ for the build. Out of curiosity what cam are you going with?

Camshaft #'s request.

I need to get the cam card for this as we had this camshaft made specifically for this application.

I dont think it is too much different than the available cams out but they did add more duration on the intake side to support the larger displacement.

I have to get that card as we need it to dial in the QuadraJet & HEI unit I have.

Ill get back to you on this!

[BillyBlaze]

schweet!

[West Texas Z]

looking good!

[RPOZ11]

Took off some small parts for assembly onto the new 496.

Everything will be bead blasted and repainted then reinstalled.

A/C Unit + Bracketry:

[RPOZ11]

Alternator Assembly :

[RPOZ11]

Power Steering Unit assembly :

[RPOZ11]

Fan & Clutch assembly :
( Going to look for a replacement clutch for this )

[RPOZ11]

Carb, Trans Dipstick tube & housing, Vacuum Modulator line & fitting, carb to brake booster vacuum line and fittings, & misc...

NOTE : This carb I had from this 73 GMC 454 motor, the carb was a 7043207; and I was told a 7043507 was correct for a smog setup in Calif.

[RPOZ11]

Thermostadt Housing (cast iron) & Engine Lift Brackets...

The one small port water hose fitting: should I drill it out for more flow???

[RPOZ11]

Battery Cable hold down bracket...

[RPOZ11]

What is this bracket used for???

I cant remember???

Alternator wiring harness to alternator?

[RPOZ11]

Originally Posted by RPOZ11

Also, I posted a wanted ad but havent gotten any results so I am going to add it to my build thread here in hopes someone might have what I need here:

http://67-72chevytrucks.com/vboard/c...ct=3767&cat=19


I need the Bracket and a correct GM used working EGR unit for my 73 Chevy truck.
looks like the one in this picture below:



OR, If you have the very same intake with the EGR that I need as shown, PM me as I might take it.

TTT

Anyone got one of these setups???

I am still looking for this EGR and bracket + bolt factorty setup.

HELP....

[Desert1957]

Originally Posted by RPOZ11

Carb, Trans Dipstick tube & housing, Vacuum Modulator line & fitting, carb to brake booster vacuum line and fittings, & misc...

NOTE : This carb I had from this 73 GMC 454 motor, the carb was a 7043207; and I was told a 7043507 was correct for a smog setup in Calif.

FYI -Just thought I would mention , while looking at your carburetor picture I noticed the base gaskets is severly burned up. On some of these early Big Block motors there is a separate steel shim that goes between the intake and the gasket to prevent this burning. Any good parts place should have a listing. If you can't find a part number I might have a listing.

Desert

[RPOZ11]

Ah yes, I do recall using those shims before.

I tore these parts from the 73 GMC parts truck/motor I have.

To make things a bit easier on the reinstall, I am swapping from this GMC 454 motor the necessary parts to install onto the new 496.

Aiming for a more trouble free install.

This particular original carb I will not be using.

We are going with a later 70's to 81 style where the vacuum choke piece is and install an electric choke. Sooo much easier in the morning and for cold starts.

At that pointe, that is when we will select the proper gaskets for this.

We did install an Edelbrock 2.0 Performer intake, with the EGR provision, with oval intake ports to match the 781 heads.

[TheBlueBomber]

Any updates since 2010?