73-77 GMC big block,worth buying?

[bobs409]

I just found a very good running big block in a 73-77 GMC 6000 series dump truck. Possibly has 67,000 but can't prove that. Can get for $400 I am assuming it's a 454? It's in a junkyard but the owner of the yard used it for a while and said it start right up everytime and runs very good. (he's trustworty so I have NO doubts)

Would you guys bother with this? Is it worth $400?

If I get the go ahead from you guys, I was thinking of doing a few mods and putting it in my 72 Malibu. It would replace an existing 307 so should be some improvement anyway. :D

Can these truck engines be built up for performance? I guess it has a taller deck but is that really a big deal?

Thanks for any advice,


Bob

[bobs409]

Having a tough time finding any websites about these trucks. Does anyone know of any?

Looking for a way to determine the exact size of this engine. Suffix codes?

Thanks,


Bob

[walkerheaders]

if it does have the tall deck...it's probably a 366. could be a 427 but not likely. the only way it be 454 would be low deck and if you reach up INSIDE the 8" balancer, you will find a counterweight. 454's are external balance. the only thing good in a 366 is the crank, rods and maincaps. maybe the heads. not sure how to spot a 427 from the outside. but they are nuetral balance like a 366 and every other chevy engine except 400sb. hope this helps to make it clear as mudd.

i would grab it anyway for that price. if it's a low deck block, it's definately worth having. also look for a pair of giant threaded 1/2" npt pipe holes above the oil filter. this is a sure fire way to spot 4 bolt caps. (it feeds the oil cooler on HP models)

[Tic's60]

http://www.fastnuf.com/bbccastingnumbers.html

You can make some large cubic motor with tall blocks!

[bobs409]

Thanks guys. I am amazed at the lack of websites on these trucks. I mean, zero & ziltch! I searched and searched and can't find anything on them. It's like trying to find 409 information before I created this site! :p

What I will do is print out a list of the suffix codes I found on some sites and take it with me. If it's a 366, it will stay, a 454, it comes home with me :brow but what if it's a 396, 427? Are they worth bothering with?

If it can't be hopped up later, I'm not interested. I thought I'd use it for a while and later on, build it up to perform. Can that be done with the 396, 427?


So if I read correctly, if it's a 454 truck engine, that can be built up? Any drawbacks to it being a truck engine?


Thanks for any further help,


Bob

[SSpev]

if it is an original engine to the truck, it is a tall deck. never saw a 454 in a big truck. Fastest way to tell a tall from a short is to look at the water pump mount area. If the pump is on, the deck of a 454,427,396,402 will be right against the water pump. A tall deck is about 1/4 inch away. The deck height is .400 more. You can make a 496 with LONG rods and more. I think all TD had 4 bolt mains and forged cranks. Don't count out the heads. Carcraft recently made 500 HP wit truck heads. The 366 block is scrap.

[SSpev]

The first is a tall. Look how far the water pump bolt is from the deck. 2nd is a short. The hole is much closer.

[bobs409]

Thanks Thomas. I'll put this info to good use. :D

My luck it's a 366. There is another one there too but not sure on it's condition. Will check that one too.


Bob

[petepedlar]

The tall deck 427's do make good power and are a good engine. I don't think the heads are that good but can be replaced. The only thing that is bad about a tall deck is that there are only expensive after market intakes for them. A std BBC intake won't fit........... kind'a falls into the valley.

Dave

[SSpev]

you can make a 496 with either block. longer rods in a tall deck. 496 is 60 over.
intakes are limited to single plane. you can run spacers and use any intake. talls take a tall distributor.

truck intakes have 2 t-stats

hear is the artical in CC
http://www.carcraft.com/techarticles/ccrp_0803_big_block_cylinder_heads/index.html

[raymar58454]

Bob, what kind of torque/H.P. you want?? 454 very mild build gives you 60 more torque/60 HP right off the bat. Street? strip? or just mild? Personally I would do 454. For street I like ovalport heads. Look for book How to Hot rod 454 or big block, something like that at your local parts store, gives you different head and block numbers. By the way I have for sale the 454 out of my suburban listed in items for sale, not sure how to get it out to you though. I'll send you a PM,
Ray

[bobs409]

Looks like it's staying where it is. Checked the code and it's a 75 or 76 366. (AHD) Oh well, think I'll buy the 63 some sheetmetal instead. :D Getting ready to dive into the driver quarter. Thankfully all the parts are finally available. :deal



Bob

[bobs409]

Bob, what kind of torque/H.P. you want?? 454 very mild build gives you 60 more torque/60 HP right off the bat. Street? strip? or just mild? Personally I would do 454. For street I like ovalport heads. Look for book How to Hot rod 454 or big block, something like that at your local parts store, gives you different head and block numbers. By the way I have for sale the 454 out of my suburban listed in items for sale, not sure how to get it out to you though. I'll send you a PM,
Ray


Ray, I wasn't really on the lookout for a big block, I just found this one in the junkyard and it got me thinking...


Bob