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1968 Camaro 1975 camaro
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Discussion Starter · #1 ·
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Well for thr 68 I sourced some 781 heads for 75 bucks. Guess I'll use them since the wife wants to keep the car.
278489

A gen vi block for 300 and now I'm building a big block. My 75 has a 489 pretty potent street engine... This engine will be much milder with a goal of 450hp instead of 640 like the 489.
My goal is to buikd this as a 'day 2' car(is what I call it).
Idea for the build:
Have the 781s gone through and have 2.19/1.88 valves installed and a nice bowl cleaning.

Friend has a factory forged crank for a 502 he will sell me that has a nic and one of the bearings that should be able to cleanup at 0.010.

Bore 0.030-0.060 over to clean some putting in the cylinders from the previous owner and use h581cp pistons which should bring compression to 10:2 roughly.

Cam--factory roller set up with new springs. Hoping the clay Smith old school cam which is
Duration @ .050 - 229/241
.200” Duration 145/151
Lift .590/.570
Centers 105/113
LSA 109

OR A ZZ502 cam which is
.050" tappet lift (intake/exhaust) is 224/234

Lift with 1.7:1 rocker ratio (intake/exhaust) is 527/544.
Intake will be a holley strip dominator and a sniper efi set up(or skemrhibf something similar)
Exhaust will be exhaust manifold(yes I know hurts power) and a 2 1/4 inch system out to tail pipes(until I can go 2 1/2)

The car will have a well built th350 and a 8.2 10 bolt with 3.73 or 3.55 gears(I already have thr th350 and 10 bolt they will be temporary until I can upgrade them later).

Thr current set up just isn't doing it for me. It's a 327 with 9.25:1 compression, L79 222/222. .447/.447 114lsa cam, edelbrock 2101 intake and exhaust manifolds with a 2 1/4 inch exhaust with a powerglide and 3.08 10 bolt.
This will kind of be my build thread. It may take several months but I'll get it done!
278490
 

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If you are only looking for 450 hp you can probably save a few dollars and reuse the smaller valves that come with the heads.

With your ho goals, doubt you will pull a lot of rpm but you will have a lot of low end torque. You might consider 3.31 gears or 3.55.
 

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68 Camaro SS/RS, 454 BB 4 speed, 3.73 Posi, new paint, motor mods , trans and diff assembly. 2" Drop
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🍹 I have same block and similar build but went with Bowtie aluminum heads and Comp 412 roller cam (thank you pandemic parts availability). Post your progress as you go.
 

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1968 Camaro 1975 camaro
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Discussion Starter · #4 ·
If you are only looking for 450 hp you can probably save a few dollars and reuse the smaller valves that come with the heads.

With your ho goals, doubt you will pull a lot of rpm but you will have a lot of low end torque. You might consider 3.31 gears or 3.55.
I actually thought about 3.31s as well depending on what's available when I redo the rear end and what I find. I will drag race it a couple of times but not trying to be the fastest, just have the most fun.
Do you think the stock valves will make that kind of power?
 

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I actually thought about 3.31s as well depending on what's available when I redo the rear end and what I find. I will drag race it a couple of times but not trying to be the fastest, just have the most fun.
Do you think the stock valves will make that kind of power?
With the right cam, YES
 

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Discussion Starter · #6 ·
With the right cam, YES
Cam will be very mild in this engine. My 75 is the "hot rod" according to my wife. I am building this for her to enjoy as well. I would love to go wild, but she wants it mild LOL
I am thinking a zz454 or preferrably a zz502 cam honestly. I know it is easy on valve train parts and pretty mild idle.
 

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Idea for the build:
Have the 781s gone through and have 2.19/1.88 valves installed and a nice bowl cleaning.
Have you thought about using a set of aluminum heads for this build?
The reason I ask, I have a set of ProMaxx heads on my car and they are a decent head.
I had Scott Foxwell assemble them. Mine are rectangle port but I think they make an oval set if you want to go that way.
I think they are a good bang for your buck and by the time you rework your cast heads, you may have been not far off from buying a set of those heads.
Just a thought.
 

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Just rebuilt my 468 and HP is 425. 1973 block and heads, was bored 30 crank turned 20, cast domed pistons, 10:1 compression, valve job, new bearings. Same cam, Crane HIT 292, roller tip rockers. Headers, Air Gap intake, 750 Holley VA, 4 SPD Muncie, 3:42 gears. Builder has 30 years experience and took into account what type of driving I do and said I did not to spent any more money with the driving I do. Cost $1800 and built in 3 days.
 

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Discussion Starter · #9 ·
Have you thought about using a set of aluminum heads for this build?
The reason I ask, I have a set of ProMaxx heads on my car and they are a decent head.
I had Scott Foxwell assemble them. Mine are rectangle port but I think they make an oval set if you want to go that way.
I think they are a good bang for your buck and by the time you rework your cast heads, you may have been not far off from buying a set of those heads.
Just a thought.
I've been thinking about it, I an going to her a price for fixing these first and then may look into the Promax or something similar
 

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Discussion Starter · #10 ·
Just rebuilt my 468 and HP is 425. 1973 block and heads, was bored 30 crank turned 20, cast domed pistons, 10:1 compression, valve job, new bearings. Same cam, Crane HIT 292, roller tip rockers. Headers, Air Gap intake, 750 Holley VA, 4 SPD Muncie, 3:42 gears. Builder has 30 years experience and took into account what type of driving I do and said I did not to spent any more money with the driving I do. Cost $1800 and built in 3 days.
My goal is to make around that on that line of budget. Just not sure how much machine work will be though
 

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Just rebuilt my 468 and HP is 425. 1973 block and heads, was bored 30 crank turned 20, cast domed pistons, 10:1 compression, valve job, new bearings. Same cam, Crane HIT 292, roller tip rockers. Headers, Air Gap intake, 750 Holley VA, 4 SPD Muncie, 3:42 gears. Builder has 30 years experience and took into account what type of driving I do and said I did not to spent any more money with the driving I do. Cost $1800 and built in 3 days.
Did this cost include new pistons? Did you re-use the valve springs keepers, rockers etc? I assume the intake, carb and headers were re-used.
 

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Discussion Starter · #12 ·
Did this cost include new pistons? Did you re-use the valve springs keepers, rockers etc? I assume the intake, carb and headers were re-used.
At 10:1 I think he went with the same pistons I am planning on going with--H581cp which arent crazy expensive.

I am going to use the zz454 or zz502 am so I can retain the stock roller set up.
 

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I did a 427 a couple years ago. Forged pistons .60 over. Crank .10 under. Torque Plate honed. new roller cam etc. It was around $5K with the parts and machine work
 

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The reason I had the 5000 mile engine rebuilt is because it detonated due to the poor build of the PO. 2 cracked pistons with no other damage. I replaced the like same cast dome pistons, rod and crank bearings and lifters. Did turn the crank. Heads were examined and exhaust valves replaced, springs were tested as well and were fine. I did discuss what pistons to use and he said the failure rate is the same for forged or cast, most all new muscle cars use cast as well. The type of driving I do doesn't need more expense. Before the issue the car had plenty of power. All the components, intake, headers were reused. I should mention this is a 69 Chevelle SS with all original sheetmetal and in the 15 years I have owned it I have only put on 3k miles. With 8 cars, they don't get driven as much as they should. Mostly my 69 RSSS vert Camaro I have owned for 43 years and my BB C-10 that I have had for 32 years.
 

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View attachment 278491 View attachment 278492 Well for thr 68 I sourced some 781 heads for 75 bucks. Guess I'll use them since the wife wants to keep the car.
A gen vi block for 300 and now I'm building a big block. My 75 has a 489 pretty potent street engine... This engine will be much milder with a goal of 450hp instead of 640 like the 489.
My goal is to buikd this as a 'day 2' car(is what I call it).
Idea for the build:
Have the 781s gone through and have 2.19/1.88 valves installed and a nice bowl cleaning.

Friend has a factory forged crank for a 502 he will sell me that has a nic and one of the bearings that should be able to cleanup at 0.010.

Bore 0.030-0.060 over to clean some putting in the cylinders from the previous owner and use h581cp pistons which should bring compression to 10:2 roughly.

Cam--factory roller set up with new springs. Hoping the clay Smith old school cam which is
Duration @ .050 - 229/241
.200” Duration 145/151
Lift .590/.570
Centers 105/113
LSA 109

OR A ZZ502 cam which is
.050" tappet lift (intake/exhaust) is 224/234

Lift with 1.7:1 rocker ratio (intake/exhaust) is 527/544.
Intake will be a holley strip dominator and a sniper efi set up(or skemrhibf something similar)
Exhaust will be exhaust manifold(yes I know hurts power) and a 2 1/4 inch system out to tail pipes(until I can go 2 1/2)

The car will have a well built th350 and a 8.2 10 bolt with 3.73 or 3.55 gears(I already have thr th350 and 10 bolt they will be temporary until I can upgrade them later).

Thr current set up just isn't doing it for me. It's a 327 with 9.25:1 compression, L79 222/222. .447/.447 114lsa cam, edelbrock 2101 intake and exhaust manifolds with a 2 1/4 inch exhaust with a powerglide and 3.08 10 bolt.
This will kind of be my build thread. It may take several months but I'll get it done!
This combo is good for at least 500 hp. You'll be lucky to not destroy that TH350 trans.
The exhaust will kill about 30 hp.
The ZZ502 cam is a great cam but very expensive new ($400). I found one used for $150.
 

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Discussion Starter · #16 ·
This combo is good for at least 500 hp. You'll be lucky to not destroy that TH350 trans.
The exhaust will kill about 30 hp.
The ZZ502 cam is a great cam but very expensive new ($400). I found one used for $150.
That's my goal is to find one used
I want this to be a pretty mild set up. I'm used to the power in my 75 so trying to drive a 327 with a powerglide and 3.08 gears suck. I am hopeful to get the transmission in within the next two weeks or so and see how much that chnages the car
 

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That's my goal is to find one used
I want this to be a pretty mild set up. I'm used to the power in my 75 so trying to drive a 327 with a powerglide and 3.08 gears suck. I am hopeful to get the transmission in within the next two weeks or so and see how much that chnages the car
I think Turbo 400's are cheap; why not build one of those ? They are indestructible !
That Turbo 350 will be toast behind a decent big block.
 

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Discussion Starter · #19 ·
500 - 525 HP is typical
of a street 383.
Lol no it's not. It borders streetable due to the large cam that requires.
Now..... If we start talking about strikers it's not any different to stroke a 454 to a 489 which easily makes 600hp with 600ftlbs of torque with a VERY mild idle.
 

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Lol no it's not. It borders streetable due to the large cam that requires.
Now..... If we start talking about strikers it's not any different to stroke a 454 to a 489 which easily makes 600hp with 600ftlbs of torque with a VERY mild idle.
Wrong. The Blueprint 400 we put in my buddy's 69 dynoed at 518 HP with very good street manners.

Everything for BBC cost more. Heads alone are almost double the cost of a comparable SBC head.

Not saying I don't like BBC. I think they are great. Just computing bang for the buck.

If you want real power go LS. I had to say that.

Good Luck with your build. Looking forward to seeing the progress
 
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