1946 gmc

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Man, that looks nice! I'm glad you posted pix of that engine bay. I've been running thru my mind figuring how close everything will be putting a BBC motor in my 46. I was wondering if any inner fenders might have to be cut.

Yeah, I used to have a different alternator bracket so the inner fender on the drivers side could have been cut less if I always had the one I do now. But the openings in the inner fenders give me access to the timing marks, fuel pump, power steering pump, belts, etc. It could be cleaner, but it's functional and I'm always making it just a little bit nicer.
 
Man, that looks nice! I'm glad you posted pix of that engine bay. I've been running thru my mind figuring how close everything will be putting a BBC motor in my 46. I was wondering if any inner fenders might have to be cut.

My engine could be placed about 4" further rearward. It is where it is for a few reasons (floor clearance among others), and it's already pretty far back compared to the axle center line. However, the BBC is about 4" or so wider than my Buick. That could make things quite tight, depending on where the engine is placed.

I can tell you that the engine bay feels pretty cramped when you have your arm jammed in there to change spark plugs or tighten the exhaust manifolds, or lift a cylinder head down onto the block.

Engine dimensions comparison for reference: http://www.carnut.com/specs/engdim.html
 
If you have any larger engine, it would be helpful for access. I can do most regular maintenance from the top, but my power steering pump is actually slightly under the fender. To remove the power steering lines from the box, do shock or suspension work, fuel pump, etc., I need more access.

Keep in mind that the 41-46 Chev trucks had openings in the hood side panels. 41-46 GMC's do not. I find on hot days, the heat really wants to stay in the dome of the hood. Any engine compartment ventilation can help with that. Above about 95°F I just take my hood off.
 
Thanks man for the info. I've been so busy I never have really started this project and it's wearing on me. One of these days in a fit of not enough to do...:D... I'll make a stab at it.
 
Did some more carb tuning tonight and went to the local cruise night. I'm waiting on some more carb parts, but it's getting close. The throttle response is crazy at parking lot speeds, it's a tire burner at low speeds, and my hesitation is almost gone. With any luck I'll have it fully sorted soon.

Still haven't put the hood back on, the engine looks so good and I'm still messing with it.
 

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I love replacement parts...

Put a new larger accelerator pump and squirter in. It worked way better but still had the stutter. So I put the next bigger size in, a 40. 40 requires the hollow screw, and it comes with it. Put it in and the squirter doesn't squirt. Wouldn't start, accelerator pump is hard as a rock. I had changed the pump cam so thought maybe I screwed something up. Took it apart, and realized that the screw for the squirter was too long and held the needle under the squirter nozzle down. In the process, I learned that my #40 nozzles were dropped in transport, both had the brass tubes pinched at the end. So I would have been very lean on one half had I not noticed that. So I put it back together with another squirter, drove it down the road and it whistled at part-throttle. What the heck? I tried a few things and realized it also whistled slightly with the engine off. Turned out at some stage I got about an 1/8" long tear in the pump diaphragm. That's not all, though. I also got a slight tear in the rubber check valve diaphragm. Probably from the high pressure when that nozzle screw was preventing flow.

More parts on the way. Getting closer, and learning a ton about performance carburetor tuning.

I looked at the carburetor squirter on the Holley Street Avenger on my 62. It had an off-idle stumble slightly. Turned out it had a bad gasket between the nozzle and carb body from the factory, so it was pouring fuel through there. Boy, throttle response improved when I fixed that!
 
Damn, if you didn't have crappy luck you wouldn't have any at all!! Sounds like progress though!
 
Damn, if you didn't have crappy luck you wouldn't have any at all!! Sounds like progress though!

You're not kidding. Friday my buddy asked me to help him put the side window back in his 36 Nash. Easy, right? I ended up having to weld up part of the crank mechanism for him that he didn't know was broken until the window crank wouldn't turn the gear. A 15-minute job turned into a 3-hour adventure by the time we disassembled and reassembled it all.
 

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