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Discussion Starter · #1 ·
I'm rebuilding an all stock 1978 Corvette (auto). Car has a nice eye and will just be a weekend hotrod.
Engine has been bored .030 and an eagle 383 rotating assembly ordered.
Just looking for some Cam and Head suggestions, would like to see 400HP+.
I'm currently leaning towards the 195cc BluePrint heads from summit: yes/no:confused: I would like to stay under $1000. for the heads.
I'm planing on replacing the factor exhaust with duel exhaust.

Thanks in advance for the help!! :D
 

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Wrench Turner
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400 HP on a 383 is a walk in the park, but, we need to know more about your parts.Which pistons are you using & their volume in cc's.You can't choose a cam, or, heads for that matter without that info, along with the piston to deck hgt @ TDC. You have to know what your actual compression ratio will be.
Another problem I see is the exhaust.Using stock manifolds is gonna choke most cams that would get you to your HP goals.
 

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I'm rebuilding an all stock 1978 Corvette (auto). Car has a nice eye and will just be a weekend hotrod.
Engine has been bored .030 and an eagle 383 rotating assembly ordered.
Just looking for some Cam and Head suggestions, would like to see 400HP+.
I'm currently leaning towards the 195cc BluePrint heads from summit: yes/no:confused: I would like to stay under $1000. for the heads.
I'm planing on replacing the factor exhaust with duel exhaust.

Thanks in advance for the help!! :D
One of several things that you need to know in order to install the right cam in a motor is the static compression ratio. In order to figure the SCR, you need these values:
Bore
Stroke
Combustion chamber cc's
Head gasket bore and compressed thickness
Piston crown configuration and cc's of dome, eyebrows or dish
Distance from crown of the piston to the block decks where the heads bolt on, with the piston at top dead center.

Once you know the SCR, you will also need the following:
Will the vehicle be used for street or strip or a little of both?
What will be the weight of the vehicle?
What tire size?
What gear ratio in the rear end?
What transmission?
What rocker arm ratio?
What is the block deck height?
What intake manifold and what carburetor?
What type of cam, flat tappet hydraulic, flat tappet solid lifters, roller hydraulic or roller solid lifters?

If you will bless us with these values, we can figure the SCR and then suggest a cam for you.

If you will expand your budget on heads to just under $1200, you can buy arguably the best aluminum heads on the planet, the Profiler 23 degree heads, 195cc intake runners.
https://www.profilerperformance.com/176-sbc-23-degree-heads.html
 

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Discussion Starter · #7 ·
Do you plan on running the stock hood. this is an issue at those power levels not many combos that will clear the stock hood. Its really tight in there.

Definitely planning on keeping the stock hood.
Hows 350 sound..

Might be harder to get the rpm intake under the stock hood with an air cleaner on it. Drop base i dont think it fits but the proflo might squeeze in there. I do think there is a combo that allows the rpm intake and and air cleaner to fit but not sure of the part numbers.

Without the good intake you will be hard pressed to reach the 400 hp level.

Also where are you located?
350 doesn't sound as good as 400, but I could live with it.
Located in Georgia.
 

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Wrench Turner
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With the pistons listed for your rotating assembly, the 64cc heads linked above is gonna put your compression ratio over 11:1.That's what happens when ppl are so anxious to "help"& don't take time to really look at the entire combo of parts you're using.While that compression would be workable with very careful cam selection, you would be better served by choosing a head that is available in a larger chamber, or, switching to a piston with more volume.The heads that Tech linked above, Profiler, are available in a 72cc chamber & are a much better head even tho slightly over your budget.They would make your HP goals alot easier & even with less cam needed with the other head to get the same results.
 

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Definitely planning on keeping the stock hood.
That's unfortunate. I have never let sheet metal or fiberglass parts of a car stand in the way of performance parts. You would do well to use a modified hood that would allow you to use a high-rise dual-plane intake manifold such as a Weiand 8150 or Edelbrock 7101. Such a manifold should be worth 40 horsepower over a low-rise dual-plane with a stock hood, so do as you wish.
 

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Wrench Turner
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You can make 400 HP with 10:1 compression, so, why run over 11:1 just so you can use that head & again "make it work"? Why not just use the rite parts along with a safer easier to deal with compression & cam.Why run a bigger than needed cam & excessive compression just so you can use a cheap head.Why "make it work" when the correct parts will work better without having to make it work.There are other heads available with more volume that will work without being made to work.
 

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More for Less Racer
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Blueprint's head is an offshore casting, but it is a clean sheet effort designed by BluePrint's own people. While I haven't touched one personally, word around the engine forums is that it is a decent piece and no where near as poorly made as say ProComp.

Appears to be on the same level as ProMaxx, which is another import casting, finish machined and assembled here in the US. BluePrint does the same thing.

MTA, you may want to look at PROMaxx heads also, they have a 72cc chamber available, the 185cc intake runner would probably be right up your alley.

You may want to consider a Weiand Accelerator intake, I normally shy away from the Weiand Accelerator/Edelbrock Torker II because as short single plane intakes they don't work nearly as well as a good tall race single plane or even the Weiand Warrior/Edelbrock Performer RPM dual planes....but with the stock Corvette hood it is about all that will fit.
 

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Wrench Turner
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As you're finding out, it's always best to build a motor on paper & do all the math before you start actually buying parts.
For the type build you are looking at with an aluminum head, I would want to limit my compression to around 10.5:1.While 11.2:1 doesn't sound like a big jump, it is & there won't be a big performance gain from doing so.You gain more performance & power with the lower compression & the ability to tune the engine with a better timing curve than boosting compression. While raising compression on an 8.5:1 motor to over 9:1 can have a big impact, it is less effective in higher ranges.
If you were shooting for 500 HP, then it may be needed due to the cam you would be looking at, but, for 400 HP 383, it's just not needed, or, a very good idea.
IIRC, I don't think the Blueprint heads come in a larger chamber head.They may tho.The ProMaxx is a good alternative & will perform just as well as that NKB for the approx same $$ & not provide you with excessive compression.If you could possibly swing another $200 over your $1000 budget, the Profiler would be a much much better choice all the way around.Quality & performance.
 

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Discussion Starter · #13 ·
For what it's worth Jegs advertites this kit as having the following Comp. Ratio 58cc/64cc/76cc: 11.4/10.7/9.4
Summit has it list as 10.38:1 on 64cc heads.
Guess I'll know more Wednesday when I have the actual parts in my hand.
 

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Wrench Turner
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For what it's worth Jegs advertites this kit as having the following Comp. Ratio 58cc/64cc/76cc: 11.4/10.7/9.4
Summit has it list as 10.38:1 on 64cc heads.
Guess I'll know more Wednesday when I have the actual parts in my hand.


Those compression ratios are based on & assuming a .025 piston to deck & using a .041/.039 headgasket,which will set your quench to the mid .060" range.This will make your motor more detonation prone than the higher compression provided with a .035" to .045" quench distance.


You will be better to lower the compression to 10.5:1,or,under & gain your performance with proper tuning & timing.There is a lot more to gained by being able to set up a good timing curve than raising compression & a lot less risk.Being able to add a few more degrees in timing will net you much better gains than a rise in compression.
 

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Wrench Turner
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That would be a better option & would get you into the 10.6:1 range.
It's the same head as was linked earlier,but,Skip uses a valve with more dish to it to provide some additional volume.It would certainly be an option.
What machine work has been done to your block?Have the decks been cut?You will need to measure the piston to deck hgt with your new rotating assembly to get an accurate answer & then choose headgaskets,etc to achieve the best quench distance possible.


As for your intake,I'm not a vette guy,so,I'm not sure what the maximum hgt you could use is.I know Brodix has their HP1 intake & it has a hgt of 4.25",which,IIRC,it just barely shorter than the regular Performer intake.
Have you considerd possibly adding a small scoop to your hood?
 

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Discussion Starter · #17 ·
I've read that a Edelbrock Air Gap RPM #7501 will fit under the hood if you use a drop base air cleaner assy.

This is more a project to show my son how to build an engine, but while I'm at it might as well make it a Hot Rod!! :D:D
 

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Discussion Starter · #18 ·
every point of compression below 13:1 is worth 15 HP. Dont sound like much but its enough to feel. The motor will not actually have 11.12:1 since its going to need some cam to reach 400 hp and that cam will often lower the DCR to a very low level. But we have not got that far yet. I would not buy any head until you can figure what cam it will take to get there.

There is always a little more volume than is figured. Check the link i posted from the jeep forum you can see lots of little things control compression and i left them blank when figuring the static compression of 11.12:1

But 10.5:1 will still be fine. Will also still be about the same as 11:1.

With the torker II it will fit the hood but its intake ports will not cover the ports of the 195 cc heads in most cases its a poor match. Would work fine for oem heads but might be a tough fit for the larger heads. Since the ports are so small.

A spacer of 1 inch may fit onto the shorter intakes and help a bit but its more of the port size than anything. Of course volume is still a major issue.


With this cam and 64cc heads I get DCR 8.47:1 with proper quench of .040"

Thats about as close to the sweet spot as you want to get on the street. Cam is about as small i would think could get you to 400 hp level. Should be a blast to drive as well.

BareBones Retro-Fit Hydraulic Roller Cam - Chevrolet Small Block 278/288 - Lunati Power

This is one of the cheaper lunati rollers that should work well for your needs. If it falls short should still be able to go with 1.6 rockers to beef it up a touch.

Should also allow a good timing curve from re curved HEI dizzy. You will need to upgrade the distributor a bit but that will be common to ny engine that is going to make good power.

9:1 DCR is max for aluminum heads and many have gone well beyond this point but it should not be needed for this build should put you right into the best performance for the least headache range.

You could go lower if you want but not sure its going to help the larger cams required to make that power level. So I will leave it up to you.

I posted parts i did the math on and checked to be sure it will work.

The jeep strokers link has a very nice compression calculator and also figures dcr. Just use the advertised duration as it says in the directions should be fine.

I think the blueprint head is a vortec style head and needs center bolt valve covers and vortec intake pattern and headers. But not sure something to find out before ordering. Not sure of any vortec bolt pattern intakes that will fit under your stock hood. But it may be drilled for both just dont know. I also have to say if blue print told me they cast this head from old beer cans they collected themselves i still would think they purchased them from someone else. There clean sheet of paper head is kind of hard to believe. I guess its possible but would put my money into one. But one of the guys on this site recently used these heads and had issues with his accessories lining up maybe contact him and see how he likes them.

Here you go he got the answer in the last part of the post.

http://www.hotrodders.com/forum/accessory-brackets-not-lining-up-new-engine-466698.html



Well thats my two cents enjoy the flame war that will follow. PM me if you have any questions. Probably wont post any more since things always seem to get out of hand here.
Thank you for your two cents!! I've noticed discussion can get out of control on here, but so for they have been helpful.
 

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Discussion Starter · #20 ·
Are you going with a roller cam/lifter setup on this build?
That that depends on my brother in law. He said he had a set of crower roller lifters. If he don't I'll probably go with flat tap lifters........probably, nothing is set in stone on this.:mwink:
 
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