High Compression BBC for the street - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

b454rat · 10-22-2012, 08:47 PM

Late 70s/early 80s if that's second gen. Might have been cool in the 80s, but not so sure now....hard to see in pic, but rear spoiler is off a 69 Camaro...

Redcap · 10-22-2012, 09:49 PM

Quote:

Originally Posted by b454rat

I've had a bunch of Malibu's and other G bodies, but this one takes the cake. Factory stick, tach dash w/clock, black interior, buckets, console, and factory power "sky roof". I've only seen two, this one and a 78 I had when I was going to school in FLA. Never knew they existed. I have new front fenders (two guesses what the louvers are off) and found a set of doors. Still tweaking it, but runs and drives, goes pretty good, but the carb is tickin' me off....

What's under the hood of yours??

This is my first venture into G-bodies.. Got the car for free from a buddy that scored too many of them in a deal...this was the worst one of the bunch. Under the hood is a smallblock of unknown size with a Performer RPM intake and an Edelbrock carb. TH350 car with the highest ratio I've ever seen in the rear, 2.29:1....great highway car, but a turd from a stop. This coming year I have a little body work to do and it will be getting a fresh motor (have yet to determine what I want to build). Hoping to find a different rearend (8.5") with better gearing too.

clinebarger · 10-22-2012, 10:28 PM

Quote:

Originally Posted by b454rat

Late 70s/early 80s if that's second gen. Might have been cool in the 80s, but not so sure now....hard to see in pic, but rear spoiler is off a 69 Camaro...

'701/2 to '81-2nd gen Camaro

b454rat · 10-23-2012, 06:06 AM

Havta post some pics of it done. I've been trying to find an 8.5 10 bolt and never even seen one in a junkyard. Not sure if the roundy rounder guys use them or if the cars are just that rare up here. There is one sitting behind a barn, kid I went to high school with, but not sure what he is doing with it. I'm going with a 9", found two out of early Bronco's, both have 3.50 gears and posi. I had a Grand Prick with a 2.29, dog off the line but would do over 100 pretty easy....

Redcap · 10-23-2012, 01:31 PM

Quote:

Originally Posted by b454rat

Havta post some pics of it done. I've been trying to find an 8.5 10 bolt and never even seen one in a junkyard. Not sure if the roundy rounder guys use them or if the cars are just that rare up here. There is one sitting behind a barn, kid I went to high school with, but not sure what he is doing with it. I'm going with a 9", found two out of early Bronco's, both have 3.50 gears and posi. I had a Grand Prick with a 2.29, dog off the line but would do over 100 pretty easy....

The 8.5 isn't so easy to find, seeing as only the Buick Grand National, turbo T-types, '84 Hurst Olds, and the 442's of the 80's are their donors...as far as I know. Early Bronco parts around here go for a small fortune too, unfortunately. As far as the rear ratio...well, I'm turning about 2600 RPM at 90mph. It is a GREAT highway cruiser and, if I do my part, will get 20-22mpg all day long!

Ol69C10 · 10-26-2012, 12:53 AM

Sweet Malibu. Id love to build me one of those. I had an 80 Monte Carlo with an SS front clip. Freakin love the G bodies. I actually still have brrand new shocks/springs and a 'glass hood for a G body sittin in storage but don't own the monte anymore.
Posted via Mobile Device

prostreetC-10 · 10-26-2012, 11:14 AM

Quote:

Originally Posted by Ol69C10

Any input on the 6.385 rods? Or should I just run a stock length rod? Looking at rod/piston combos the price is still very similar but is there an advantage there?

Man this thread is all over the place. You can't use a 6.385 rod on a stock 4" crank with a stock piston. You will run the piston through the head. Those are stroker rods and designed to be ran with different pistons.

Ol69C10 · 10-26-2012, 03:32 PM

Quote:

Originally Posted by prostreetC-10

Man this thread is all over the place. You can't use a 6.385 rod on a stock 4" crank with a stock piston. You will run the piston through the head. Those are stroker rods and designed to be ran with different pistons.

I would not be using a stock piston. Im looking for a piston/rod combo to get more compression: 10.5 to 11:1 with stock heads that have work done.

Goin to check out your build thread tho!

Posted via Mobile Device

Ol69C10 · 10-26-2012, 04:07 PM

Hey Prostreet, you have a thread for that ram'd 460?
Posted via Mobile Device

prostreetC-10 · 10-26-2012, 04:52 PM

I do but one day I started dicking with my photobucket account and messed ALL the pics up. Let's face it......a build thread without pics just plain sucks. lol

You won't need to mess with rods to get a compression change, just pistons. Careful though.....you start thinking about replacing too many internals and then it won't make sense to not build a 496!

Welcome to the forum BTW. We have a lot of fun on here and there is some really good info floating around.

snj8198 · 10-26-2012, 05:40 PM

When dealing with longer rod and piston combos be careful not to choose a piston that has the lowest ring land intersecting through the wrist pin hole. They don't provide very good support with higher compression. Some of the KB's are a prime example of what am I talking about.

Ol69C10 · 10-26-2012, 09:14 PM

Prostreet: haha, I noticed your threads w/o pics! Complete let down. Thanks for the intro, Ive been hangin around for a few years and even had a login but hadn't used it in so long it got shut off. This is one of my fav forums.

Snj: thanks for the info, I had forgotten about that.
Posted via Mobile Device

*bk2life* · 11-02-2012, 04:04 AM

Take your 781 heads and have them surfaced, add valve springs that match the cam you are going to run, and add the bigger valves. Pretty simple stuff and shouldn’t coast much more then 2-400 in machine/assembly work. If you are any good with a die grinder you can remove casting flash in the heads and help out some. Don’t worry about port matching.
Performed rpm or wieand 1802 (I think that’s the number) intake.
Almost any cam 290-305 duration. (it’s a big block, 300 duration is “big” on a small block, not really so on a big block)
781s have big combustion chambers, youll need a small dome piston to get you anywhere between 9 to 10:1 compression. Id stay closer to 9:1 on a iron headed street engine.
Good headers, and at least a 780cfm carb.
Good solid ignition.
Get it on the dyno and get it all tuned.
Should be very reliable 500hp. Around 500+tq.
Super chevy has had several builds in the last couple of years on this exact motor. You can see the parts list, machining costs, how much they paid for a junk yard 454, etc. and as a bonus they have dyno sheets.
I am building a 489, aluminum heads, and im right at 10:1. It will be on the street, but again aluminum heads: 950cfm holley carb, 2500 stall, 4:11 gears, 2 inch headers, .580 lift/310dur roller..
Lastly don’t fool yourself BBC parts aren’t cheap.

Ol69C10 · 11-02-2012, 01:27 PM

Bk2Life: thanks for the info! Ill have to check for those articles. Have fun with that 489 build!
Posted via Mobile Device

*bk2life* · 11-03-2012, 02:48 AM

Quote:

Originally Posted by Ol69C10

Have fun with that 489 build!

unfortunately I won’t have any fun with it. I’m in Afghanistan and paying a buddy to drop it off at the machine shop, and pick it up, then install in my truck. I won’t have anything to do with it until I am home.. When I’m home got some more fabrication to do on the truck, and get it ready for a 400 mile round trip to a car show..

Ol69C10 · 11-08-2012, 10:11 PM

But deployments are where the money is made brother!

I did a pump w/ the Corps in 07-08. Stay safe and I'll pray for ya.

GASoline71 · 11-08-2012, 10:17 PM

Quote:

Originally Posted by Redcap

This is my first venture into G-bodies.. Got the car for free from a buddy that scored too many of them in a deal...this was the worst one of the bunch. Under the hood is a smallblock of unknown size with a Performer RPM intake and an Edelbrock carb. TH350 car with the highest ratio I've ever seen in the rear, 2.29:1....great highway car, but a turd from a stop. This coming year I have a little body work to do and it will be getting a fresh motor (have yet to determine what I want to build). Hoping to find a different rearend (8.5") with better gearing too.

You been holdin' out on me?

I want a G body one of these days myself. Way cool mang!

Quote:

Originally Posted by bk2life

unfortunately I won’t have any fun with it. I’m in Afghanistan and paying a buddy to drop it off at the machine shop, and pick it up, then install in my truck. I won’t have anything to do with it until I am home.. When I’m home got some more fabrication to do on the truck, and get it ready for a 400 mile round trip to a car show..

Come home safe dude... been there done that. 5 tours to the sandbox... US Navy 1986 to 2006.

Gary

10-22-2012, 08:47 PM	#26
b454rat Senior Member Join Date: May 2004 Location: Binghamton, NY Posts: 3,469	Re: High Compression BBC for the street Late 70s/early 80s if that's second gen. Might have been cool in the 80s, but not so sure now....hard to see in pic, but rear spoiler is off a 69 Camaro... __________________ 2000 GMC CCSB 454/4L80 6” lift SAS 1999 Chevy CCSB 454/NV4500 4” SAS 1999 GMC Yukon 350/4L60 6" SAS

10-23-2012, 06:06 AM	#29
b454rat Senior Member Join Date: May 2004 Location: Binghamton, NY Posts: 3,469	Re: High Compression BBC for the street Havta post some pics of it done. I've been trying to find an 8.5 10 bolt and never even seen one in a junkyard. Not sure if the roundy rounder guys use them or if the cars are just that rare up here. There is one sitting behind a barn, kid I went to high school with, but not sure what he is doing with it. I'm going with a 9", found two out of early Bronco's, both have 3.50 gears and posi. I had a Grand Prick with a 2.29, dog off the line but would do over 100 pretty easy.... __________________ 2000 GMC CCSB 454/4L80 6” lift SAS 1999 Chevy CCSB 454/NV4500 4” SAS 1999 GMC Yukon 350/4L60 6" SAS

10-26-2012, 12:53 AM	#31
Ol69C10 Registered User Join Date: Oct 2012 Location: 29 Palms, ca Posts: 34	Re: High Compression BBC for the street Sweet Malibu. Id love to build me one of those. I had an 80 Monte Carlo with an SS front clip. Freakin love the G bodies. I actually still have brrand new shocks/springs and a 'glass hood for a G body sittin in storage but don't own the monte anymore. Posted via Mobile Device __________________ '69 LWB C10: SB350 .060 over @10:1, Comp280 cam, 2800 stall, TH350, 4.11's. Want 6/6 static drop. "If at first you don't succeed, failure may be your style."

10-26-2012, 04:07 PM	#34
Ol69C10 Registered User Join Date: Oct 2012 Location: 29 Palms, ca Posts: 34	Re: High Compression BBC for the street Hey Prostreet, you have a thread for that ram'd 460? Posted via Mobile Device __________________ '69 LWB C10: SB350 .060 over @10:1, Comp280 cam, 2800 stall, TH350, 4.11's. Want 6/6 static drop. "If at first you don't succeed, failure may be your style."

10-26-2012, 04:52 PM	#35
prostreetC-10 My Carbon Footprint Join Date: Oct 2008 Location: Orygun Posts: 5,527	Re: High Compression BBC for the street I do but one day I started dicking with my photobucket account and messed ALL the pics up. Let's face it......a build thread without pics just plain sucks. lol You won't need to mess with rods to get a compression change, just pistons. Careful though.....you start thinking about replacing too many internals and then it won't make sense to not build a 496! Welcome to the forum BTW. We have a lot of fun on here and there is some really good info floating around. __________________ A quick "pedalfest" *Still getting loose (carb test)* 496 Initial fire up video!

10-26-2012, 05:40 PM	#36
snj8198 Registered User Join Date: Feb 2007 Location: Star Valley, WY Posts: 2,038	Re: High Compression BBC for the street When dealing with longer rod and piston combos be careful not to choose a piston that has the lowest ring land intersecting through the wrist pin hole. They don't provide very good support with higher compression. Some of the KB's are a prime example of what am I talking about. __________________ Steve 1971 GMC Longbox. Full Roller Stroker 489 w/ FiTech EFI, Chris Straub Cam/NV4500/205/D60/14B w. Grizzly Locker and 4.11's. 2" Lift on 33's

10-26-2012, 09:14 PM	#37
Ol69C10 Registered User Join Date: Oct 2012 Location: 29 Palms, ca Posts: 34	Re: High Compression BBC for the street Prostreet: haha, I noticed your threads w/o pics! Complete let down. Thanks for the intro, Ive been hangin around for a few years and even had a login but hadn't used it in so long it got shut off. This is one of my fav forums. Snj: thanks for the info, I had forgotten about that. Posted via Mobile Device __________________ '69 LWB C10: SB350 .060 over @10:1, Comp280 cam, 2800 stall, TH350, 4.11's. Want 6/6 static drop. "If at first you don't succeed, failure may be your style."

11-02-2012, 04:04 AM	#38
bk2life Account Suspended Join Date: Oct 2012 Location: phx, az Posts: 868	Re: High Compression BBC for the street Take your 781 heads and have them surfaced, add valve springs that match the cam you are going to run, and add the bigger valves. Pretty simple stuff and shouldn’t coast much more then 2-400 in machine/assembly work. If you are any good with a die grinder you can remove casting flash in the heads and help out some. Don’t worry about port matching. Performed rpm or wieand 1802 (I think that’s the number) intake. Almost any cam 290-305 duration. (it’s a big block, 300 duration is “big” on a small block, not really so on a big block) 781s have big combustion chambers, youll need a small dome piston to get you anywhere between 9 to 10:1 compression. Id stay closer to 9:1 on a iron headed street engine. Good headers, and at least a 780cfm carb. Good solid ignition. Get it on the dyno and get it all tuned. Should be very reliable 500hp. Around 500+tq. Super chevy has had several builds in the last couple of years on this exact motor. You can see the parts list, machining costs, how much they paid for a junk yard 454, etc. and as a bonus they have dyno sheets. I am building a 489, aluminum heads, and im right at 10:1. It will be on the street, but again aluminum heads: 950cfm holley carb, 2500 stall, 4:11 gears, 2 inch headers, .580 lift/310dur roller.. Lastly don’t fool yourself BBC parts aren’t cheap.

11-02-2012, 01:27 PM	#39
Ol69C10 Registered User Join Date: Oct 2012 Location: 29 Palms, ca Posts: 34	Re: High Compression BBC for the street Bk2Life: thanks for the info! Ill have to check for those articles. Have fun with that 489 build! Posted via Mobile Device __________________ '69 LWB C10: SB350 .060 over @10:1, Comp280 cam, 2800 stall, TH350, 4.11's. Want 6/6 static drop. "If at first you don't succeed, failure may be your style."

11-08-2012, 10:11 PM	#41
Ol69C10 Registered User Join Date: Oct 2012 Location: 29 Palms, ca Posts: 34	Re: High Compression BBC for the street But deployments are where the money is made brother! I did a pump w/ the Corps in 07-08. Stay safe and I'll pray for ya. __________________ '69 LWB C10: SB350 .060 over @10:1, Comp280 cam, 2800 stall, TH350, 4.11's. Want 6/6 static drop. "If at first you don't succeed, failure may be your style."

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