My daily driven BBC - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1971ls1longbed · 02-28-2011, 04:46 PM

I am planning on building a daily driven BBC for my 71 longbed. I was going to build a 496 with around 9.75 to 10:1 compression with a HYD roller cam around 230 with a set of 820 heads off of a 71 vette, longtube headers and depending on what I need either a 750 or 850 carb. I was wondering how this setup sounds and what kind of power I can look for based off of some of the experiences you have had
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djracer · 02-28-2011, 09:40 PM

I'm not familiar with that head but a 10-1 496 would be sweet!

**Captainfab** · 03-01-2011, 12:04 AM

Back when I built the 454 in my Burb, I used a set of the '71 402 820 casting heads. At the time (about 20 years ago) I read that those were the heads to use. They were supposed to flow the best for an oval port head.

Since this engine has over 120,000 on it, I've considered rebuilding it, but this time with a 4.250 crank. I'll be subscribing to see what others have to say about this combo.

1971ls1longbed · 03-01-2011, 09:38 AM

I was told the same thing about the 820 heads. I know the 049 and 781 are a little better but these beads were free so I can't beat that. I am going to have bigger valves and a little port and polish done to clean them up. After all these trucks are heavy so im more concerned with having a high torque number rather than a high hp
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Malibu 496 · 03-01-2011, 08:43 PM

I had a 496 in a malibu with ported 820 heads 10.75 comp and a solid flat tappet cam that made 612 hp.

1971ls1longbed · 03-01-2011, 09:01 PM

How much port work was done on those heads

Malibu 496 · 03-02-2011, 10:06 PM

I am not sure how much work was done, I got them after they were ported. I cant remember what they flowed either I think they flowed right around 300 at .600 lift and they had bigger valves.

1971ls1longbed · 03-03-2011, 01:50 AM

I hope they work I really don't want to buy new heads but I will if I have to
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02-28-2011, 04:46 PM	#1
1971ls1longbed Registered User Join Date: Dec 2009 Location: Voorhees NJ Posts: 188	My daily driven BBC I am planning on building a daily driven BBC for my 71 longbed. I was going to build a 496 with around 9.75 to 10:1 compression with a HYD roller cam around 230 with a set of 820 heads off of a 71 vette, longtube headers and depending on what I need either a 750 or 850 carb. I was wondering how this setup sounds and what kind of power I can look for based off of some of the experiences you have had Posted via Mobile Device __________________ 1971 Custom 10 LWB. 461 BBC and built 700r4 to be transplanted 1997 C3500 DRW Ext cab. 454, 4L80E daily driver

02-28-2011, 09:40 PM	#2
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,891	Re: My daily driven BBC I'm not familiar with that head but a 10-1 496 would be sweet! __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

03-01-2011, 12:04 AM	#3
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,248	Re: My daily driven BBC Back when I built the 454 in my Burb, I used a set of the '71 402 820 casting heads. At the time (about 20 years ago) I read that those were the heads to use. They were supposed to flow the best for an oval port head. Since this engine has over 120,000 on it, I've considered rebuilding it, but this time with a 4.250 crank. I'll be subscribing to see what others have to say about this combo. __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

03-01-2011, 09:38 AM	#4
1971ls1longbed Registered User Join Date: Dec 2009 Location: Voorhees NJ Posts: 188	Re: My daily driven BBC I was told the same thing about the 820 heads. I know the 049 and 781 are a little better but these beads were free so I can't beat that. I am going to have bigger valves and a little port and polish done to clean them up. After all these trucks are heavy so im more concerned with having a high torque number rather than a high hp Posted via Mobile Device __________________ 1971 Custom 10 LWB. 461 BBC and built 700r4 to be transplanted 1997 C3500 DRW Ext cab. 454, 4L80E daily driver

03-01-2011, 08:43 PM	#5
Malibu 496 Junior Member Join Date: Sep 2005 Location: Minnesota Posts: 159	Re: My daily driven BBC I had a 496 in a malibu with ported 820 heads 10.75 comp and a solid flat tappet cam that made 612 hp. __________________ 1970 blazer, street/strip project 1963 ford fairlane sports coupe 50,000 original miles

03-01-2011, 09:01 PM	#6
1971ls1longbed Registered User Join Date: Dec 2009 Location: Voorhees NJ Posts: 188	Re: My daily driven BBC How much port work was done on those heads __________________ 1971 Custom 10 LWB. 461 BBC and built 700r4 to be transplanted 1997 C3500 DRW Ext cab. 454, 4L80E daily driver

03-02-2011, 10:06 PM	#7
Malibu 496 Junior Member Join Date: Sep 2005 Location: Minnesota Posts: 159	Re: My daily driven BBC I am not sure how much work was done, I got them after they were ported. I cant remember what they flowed either I think they flowed right around 300 at .600 lift and they had bigger valves. __________________ 1970 blazer, street/strip project 1963 ford fairlane sports coupe 50,000 original miles

03-03-2011, 01:50 AM	#8
1971ls1longbed Registered User Join Date: Dec 2009 Location: Voorhees NJ Posts: 188	Re: My daily driven BBC I hope they work I really don't want to buy new heads but I will if I have to Posted via Mobile Device __________________ 1971 Custom 10 LWB. 461 BBC and built 700r4 to be transplanted 1997 C3500 DRW Ext cab. 454, 4L80E daily driver



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