My Build Thread (Sort of)

[engineer_gregh]

I waited 25 years after selling my last one to buy one of these trucks to keep. I bought and sold half a dozen or so in the 80's to make extra money while I was in the Air Force. I always had to sell them as family came first and being enlisted with three sons meant I was floating the restores on credit cards. So in January 2012 I bought what I thought was a restored truck. Big Block Cheyenne Super, Turbo 400, with A/C and tach, with the SPID in place. Cosmetically it was and is in pretty good shape. Mechanically is was not so good. So I'll start this with pictures of the truck as I bought it. For all you first time buyers; if I had gone and seen the truck in person and done a close inspection I probably would have passed on it missing all the fun I've had over the past three years.

[engineer_gregh]

a few more

[engineer_gregh]

I didn't drive the truck very far in the beginning because I wanted to make sure it was reliable. Well it wasn't and it stranded my numerous times. The gas tank was full of gunk as the truck had done a lot of sitting. After beating my head against the wall thinking it was electrical I changed the gas tank and blew out the fuel lines. It ran much better. Bought the gas tank from LMC along with a new speedometer; I wanted the miles to reflect zero as it was a new truck to me.

[engineer_gregh]

After driving the truck a couple of hundred miles it was obvious the transmission was oozing into gear. So off to the transmission shop. Once there I noticed the rear end yolk was slinging oil on the bottom of the bed, so I also had all the seals and bearings replaced. I don't think the transmission had ever been rebuilt or even out to the truck. The rear end is an open 3.08. The ring and pinion were in good shape.

[engineer_gregh]

Couple of hundred more miles and I was not happy with the way the truck ran. It seemed to run hot and was underpowered compared to a big block I had owned in the 80's. So I found someone I trusted to rebuild the engine. I don't have the space, tools, or experience to do it myself. Once torn down we discovered 6 402 pistons and 2 396 pistons, 4 burnt valves with bent push rods, and a crank that was so far out of tolerance it couldn't be turned. Just behind the rear lobe on the cam there was a grove cut all the way around. Believe it or not the truck actually ran ok and didn't skip at all. My mechanic has been rebuilding engines for 30+ years and was amazed it ran at all. So the rebuild begins.

[engineer_gregh]

I do believe the engine block is original to the truck. The heads are from a 65-66 325HP 396 Impala according to the numbers. The heads and intake were ported and polished.

[mechanicalman]

Originally Posted by engineer_gregh

Couple of hundred more miles and I was not happy with the way the truck ran. It seemed to run hot and was underpowered compared to a big block I had owned in the 80's. So I found someone I trusted to rebuild the engine. I don't have the space, tools, or experience to do it myself. Once torn down we discovered 6 402 pistons and 2 396 pistons, 4 burnt valves with bent push rods, and a crank that was so far out of tolerance it couldn't be turned. Just behind the rear lobe on the cam there was a grove cut all the way around. Believe it or not the truck actually ran ok and didn't skip at all. My mechanic has been rebuilding engines for 30+ years and was amazed it ran at all. So the rebuild begins.

65's and 66's used a grooved rear cam journal.

"the 1965 and 1966 big block 396 had unique rear cam bearings and required a grooved rear cam journal, most cams you buy currently are not grooved, the groove can be cut on a lathe in the last rear journal on the later cams , centered ,and its about .188 wide and .125 deep, if the cam is cut,for that oil groove the standard cam bearing can be used".[/size]

http://www.chevytalk.org/fusionbb/sh...hp?tid/311489/

I believe those heads raised the compression (98cc heads). I believe the stock heads would have had larger chambers.

[Tom Vogel]

[QUOTE= Just behind the rear lobe on the cam there was a grove cut all the way around.E]

That cam was specific to a 1965 396. That groove was for oiling on a 65 396 block which is different than later years BBs.

Sorry, didnt see post #26.

[SierraMtns]

Cool build. Its crazy why someone would use different pistons. I can't believe the things that people do sometimes.

Keep us posted and thanks for sharing.

[zamboni2354]

if you can't figure another way to do the video directly you could upload it on photobucket or youtube and simply post the link.

jeff

ps. nice truck!!

[engineer_gregh]

Hdff the headlight harness is very easy to install. Look at #13 above and you can see the half moon yellow lights at the very top of the headlights. Those are both parking and turn signals. Zamboni thanks for the suggestion for YouTube. Here's the link of how the truck sounds.

https://www.youtube.com/watch?v=Ge-F...ature=youtu.be

[engineer_gregh]

hdff I noticed in your signature you're running a 700R4 tranny. If you have 3.08 gears with 28" tires it won't really matter how much power your engine has it will be slow out of the hole. The OD tranny is great for highway speeds but cannot over come the rear end gearing and tire size when launching from a dead stop. My truck is the same with the Turbo 400 and 3.08 gears, slow out of the gate. But if I manually shift down into first at 20 mph or so its pretty strong as I'm in the power band of 2000+ rpms. Make sense?

[zamboni2354]

Sounds good. Nice truck.

I'm pretty pleased with my 3.73 rear/700r4 combo.

Jeff in long beach

[engineer_gregh]

Thanks Jeff. The 3.73 gears with the 700R4 is a great combination. You have the best of both worlds with really good take off power and low RPM highway speeds. I think I'm going to go with a gear vendors overdrive for the turbo 400 and change my gears to 3.42. I would love to have 3.73 but I don't want to change the carrier to get them.

[hdff]

i'm not sure what rear end is in it. I need to get the yoke seal fixed soon and I plan on finding out whats in there then

[mechanicalman]

Originally Posted by engineer_gregh

Thanks Jeff. The 3.73 gears with the 700R4 is a great combination. You have the best of both worlds with really good take off power and low RPM highway speeds. I think I'm going to go with a gear vendors overdrive for the turbo 400 and change my gears to 3.42. I would love to have 3.73 but I don't want to change the carrier to get them.

I used a spacer plate from a car 12 bolt to do mine. I did have to take it to a machine shop and have it surface ground from .333" down to .250".

That being said, I think with the 700R4 you will be happy with the 3.42 gears.

[EdSevered]

On the bright side, it doesn't look like she needed any body work. She sure is purtty. -Ed

[Riverdog57]

Love the Truck !!! Love the long bed .

[SKT]

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Any updates on this one?

Truck looks great, despite the unexpected surprises after purchase.

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[engineer_gregh]

I don't believe the new cam was grooved so now I'm concerned that I'll have problems in the future. Mechanicalman I hope my engine builder knew what he was doing. I've put about 4K miles since the rebuild with no issues. The gearing and transmission will be a next year project. I would like to have more power out of the hole but the truck runs and drives so good that I just can't justify spending that much money right now. The only addition I've made lately was to add a CPP rear sway bar. It did improve body roll but it seemed to make the truck ride a little rougher. The suspension is less forgiving with rough roads.

[mechanicalman]

Originally Posted by engineer_gregh

I don't believe the new cam was grooved so now I'm concerned that I'll have problems in the future. Mechanicalman I hope my engine builder knew what he was doing. I've put about 4K miles since the rebuild with no issues. The gearing and transmission will be a next year project. I would like to have more power out of the hole but the truck runs and drives so good that I just can't justify spending that much money right now. The only addition I've made lately was to add a CPP rear sway bar. It did improve body roll but it seemed to make the truck ride a little rougher. The suspension is less forgiving with rough roads.

That grooved cam was for 65-66, not sure even all of 66; you can't use a non-grooved cam in a 65-66 block. It is ok, however, to use the grooved cam on a later block like you were doing albeit not necessary at all.

No worries, the 3969854 block was for 69-72 396/402/454 2 & 4-Bolt that uses a non-grooved cam. You have the right style cam for your block.

Usually a sway bar will make it ride rougher. If you hit a bump straight on, like a speed-bump or drainage deression, it won't make a difference. You will notice when you hit a speed bump at an angle and go through a drainage depression at an angle that the vehicle will lurch back and forth sideways.

That grooved cam was for 65-66, not sure even all of 66; you can't use a non-grooved cam in a 65-66 block. It is ok, however, to use the grooved cam on a later block like you were doing albeit not necessary at all.

If you used these pistons-
http://www.summitracing.com/parts/sl...make/chevrolet

I figure your compression to be around 8.5:1, perfect for the cam you selected. Unless you used steel shim head gaskets, or had your heads milled then you are close to 9:1.

[mechanicalman]

Originally Posted by engineer_gregh

I don't believe the new cam was grooved so now I'm concerned that I'll have problems in the future. Mechanicalman I hope my engine builder knew what he was doing. I've put about 4K miles since the rebuild with no issues. The gearing and transmission will be a next year project. I would like to have more power out of the hole but the truck runs and drives so good that I just can't justify spending that much money right now. The only addition I've made lately was to add a CPP rear sway bar. It did improve body roll but it seemed to make the truck ride a little rougher. The suspension is less forgiving with rough roads.

Keep in mind that the TH400 has a 2.48:1 first gear ratio and the 700R4 has a 3.05:1 first gear ratio with a .7:1 overdrive.

The 4L80E has a 3.06:1 first gear, BTW, with a .75:1 overdrive.

I'd put in the trans first then address the rear end gears seeing how much lower the first gear is on the over-drives. For instance, if you had a 3.73:1 with the T400 you would have a 9.6:1 overall 1st gear. If you had the 3.73:1 with the 700R4, you would have a 11.2:1 1st gear.

With the 3.42:1 that you have now, with 700R4 you have 10.43:1 first gear.

T400 third gear 1:1 with 3.73:1 is 3.73:1 gas guzzler. With 700R4, 3.73:1 is 2.61:1 ratio highway cruiser. With 4L80 is 2.78:1 cruiser.

I think you will find after you change the trans that you will want a posi anyway so then you will have to change the carrier. Have you seen these style diffs? A posi that does not lock up when you don't need it.

http://www.summitracing.com/parts/dtl-913a315/overview/

[engineer_gregh]

Mechanicalman I appreciate all the great advice. I'm still running the original 3.08 right now. The rear end and transmission is a next spring project.

[engineer_gregh]

Thanks Ed. Honestly I went above and beyond what anyone else (normal driver) would have done to the truck. Wheels & tires, rebuilding a transmission that would have probably lasted if left alone, sound proofing the cab, upgraded alternator, long tube headers, bigger cam, three angle valve job, etc.. are what I wanted, and I'm sure that most on this board would have done. I'm building the truck to keep and I want to know that I can take it on long trips with no major issues. Making it mine, is another way to say it.

[PIG-TECH]

wow sharp looking truck. love the shine on the paint job. i am waiting for my garage to be built. and then i get to start fixing mine up