Very Important Question!!!!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68_396Noel · 09-14-2005, 01:42 AM

i have a 68 gmc 910 with all the options except a/c, it even has buckets. its all original and there is something i just noticed on the block when i was restoring it.......it came stock with a 396 4bbl, but this is where the question comes in, on the block it says that it is a 68 high performance 396... is this true?? do i have something here? could my truck be even more rare than i think it is?? can any one help me out. please.

stllookn · 09-14-2005, 02:01 AM

I have the same designation (PASS HIGH PERF OR HIGH PERF PASS) cast into the block behind the timing chain cover. This is an indication but not proof positive that the block had two additional drilled and tapped oil cooling holes and that it had 4-bolt mains.

68_396Noel · 09-14-2005, 02:05 AM

what kind of horsepower does it have then?? is it the 375hp like the chevelle and the camaro??

stllookn · 09-14-2005, 02:18 AM

310 hp Gross with 4-barrel and 275 hp Gross with the 2-barrel.

68_396Noel · 09-14-2005, 02:27 AM

its bored .20 over as well and it has headers too.

70GMCer · 09-14-2005, 05:57 AM

All big block motors came with that Hi Perf name stamped on the rear on the block. Why Gm did this, I don't know......

Swbman · 09-14-2005, 07:45 AM

70GMCer is right, I recently got rid of 1975 model 454 car motor and it said hi performance passenger car stamped on the heads and it was nothing special about had oval port heads.

chevyfarmer · 09-14-2005, 12:03 PM

Backing up what everyone else has said. The 454 that I am building for my Blazer has the Hi Perf stamp on it, and I got super excited as well, only to find a 2 bolt main.

09-14-2005, 01:42 AM	#1
68_396Noel Registered User Join Date: Jul 2005 Location: Canada Posts: 37	Very Important Question!!!!!! i have a 68 gmc 910 with all the options except a/c, it even has buckets. its all original and there is something i just noticed on the block when i was restoring it.......it came stock with a 396 4bbl, but this is where the question comes in, on the block it says that it is a 68 high performance 396... is this true?? do i have something here? could my truck be even more rare than i think it is?? can any one help me out. please.

09-14-2005, 02:01 AM	#2
stllookn Saving 1 truck at a time! Join Date: Aug 2001 Location: Kent, WA Posts: 6,465	I have the same designation (PASS HIGH PERF OR HIGH PERF PASS) cast into the block behind the timing chain cover. This is an indication but not proof positive that the block had two additional drilled and tapped oil cooling holes and that it had 4-bolt mains. __________________ '68 C20 Longhorn 50th Anniversary 400/TH400 '68 C20 Longhorn 50th Anniversary 468/TH400w/buckets '72 C20 Halfhorn (Longhorn w/o cab and front clip) '69 Flxible Cruiser (look up ugly in the dictionary)

09-14-2005, 02:18 AM	#4
stllookn Saving 1 truck at a time! Join Date: Aug 2001 Location: Kent, WA Posts: 6,465	310 hp Gross with 4-barrel and 275 hp Gross with the 2-barrel. __________________ '68 C20 Longhorn 50th Anniversary 400/TH400 '68 C20 Longhorn 50th Anniversary 468/TH400w/buckets '72 C20 Halfhorn (Longhorn w/o cab and front clip) '69 Flxible Cruiser (look up ugly in the dictionary)

09-14-2005, 05:57 AM	#6
70GMCer Senior Member Join Date: Apr 2005 Location: Joppa, Maryland Posts: 4,408	All big block motors came with that Hi Perf name stamped on the rear on the block. Why Gm did this, I don't know...... __________________ 1997 GMC Sierra Ext 1965 Mustang

09-14-2005, 07:45 AM	#7
Swbman Senior Member Join Date: Mar 2004 Location: Tulsa,Oklahoma Posts: 606	70GMCer is right, I recently got rid of 1975 model 454 car motor and it said hi performance passenger car stamped on the heads and it was nothing special about had oval port heads. __________________ 1961 BUICK LESABRE 1968 CHEVELLE SS 396 1969 BUICK RIVIERA GS 1971 2 WHEEL DRIVE BLAZER 1971 4X4 BLAZER 1971 SHORTBED CHEYENNE FLEETSIDE 1971 SHORTBED 4X4 FLEETSIDE ** ...My Ebay

09-14-2005, 02:05 AM	#3
68_396Noel Registered User Join Date: Jul 2005 Location: Canada Posts: 37	what kind of horsepower does it have then?? is it the 375hp like the chevelle and the camaro??

09-14-2005, 02:27 AM	#5
68_396Noel Registered User Join Date: Jul 2005 Location: Canada Posts: 37	its bored .20 over as well and it has headers too.

09-14-2005, 12:03 PM	#8
chevyfarmer Registered User Join Date: Feb 2005 Location: Owosso, Mi Posts: 242	Backing up what everyone else has said. The 454 that I am building for my Blazer has the Hi Perf stamp on it, and I got super excited as well, only to find a 2 bolt main. __________________ 67 short wide 355ci 3 on tree 69 short wide 250ci 3 on tree 68 long wide 283 3 on tree 72 2wd Blazer project 454 5 speed

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