If it is in fact true that the Blueprint heads are drilled for both the old and vortec intakes, then I have the option of running my factory cast iron intake !
Wonder what effect the factory cast iron manifold wiould have on HP/Torque of the 396 Blueprint ?.
I'm only interested in the most torque I can get from idle to 4-5000 rpm...... for strong street driving.... so maybe not too bad ?

 

From my understanding Vortec ports are slightly taller and a different angle then a standard SBC head. To me it's silly to spend money on a engine with 220cc heads only to handicap it with a mismatched intake. Being that you are mostly looking for a increase in torque, maybe look into a 383 short block and freshen up your existing heads. Just a suggestion.

 

BTW, what's your rear axle ratio?

 

Standard 3:31 rear

 

Sniper II does not fit a drop base air cleaner very well at all.
But they have a Sniper quadrajet is practically a bolt-in on a C3. The fuel fittings and linkage allow a drop base.
Now you need to find a 4.1" spreadbore intake for that.

 

Blueprint engines take either the old style intakes or the vortec style . So you could use your original 327 intake on the new 427 sbc

 

The Blueprint package that I wanted to purchase, comes with the sniper 2. I'd like to take advantage of modern technology if possible..

Holley sells a 1" drop base designed for the sniper
https://www.holley.com/products/fuel...C-B7Tt6BNrhlBT
This is 1" less drop than what you guys have been suggesting, so now I'm back to hood interference issues.
Is it the Sniper fuel inlet fittings, or the throttle linkage that hits the larger 2" drop air clener base ? I could "clearance" the 2" drop base to clear fuel fittings, but the throttle linkage might be harder to deal with.

Also, has anyone put an older style intake on the Blueprint vortec style heads ?
It sounds like it will bolt up, but do the ports match up reasonably well ?

I guess I could buy a Blueprint long block, and build something with the sniper quadrajet on my factory cast iron intake, but that sounds like a lot of compromises to make for hood clearance.

My hope was that my 396/sniper 2 package could be made to fit with the performer 2701 and a 2" drop base..... but now I might not be able to get the 2" drop base to work.
Any feedback on the Sniper 2 and a 2" drop base would be "greatly" appreciated..... also need to explore further the port matching issues of an older style intake on the Blueprint heads.

I'm glad I asked questions before pulling the trigger.

TIA

 

The sniper II is a real hot mess getting to fit a C3. With the Holley sniper A/C base, you will eat up hood clearance, or be forced to run a shorter 2.5" or less air filter. Chokes off airflow and is definately not ideal. The fuel fittings are a PITA to fit a 2.0" drop base. The air pipe to the air cleaner is impossible to fit. It hits the fuel line. So that pipe needs to be removed, relocated, or run a valve cover air filter.

Here is a video of a Quadrajet version of the sniper going into a stock 1970 C3 with stock hood. Falls into place even with the stock low profile open element air cleaner. Valve cover air pipe fits also and looks stock. Which the Sniper II definately does not. Check out how much lower the fuel inlets are. And it fits a spreadbore intake without an adapter. You definately do not want to run a 3/4" high spread to square adapter.


Why buy something that is going to be a problem to fit? Working with a guy now with an LS5, and a sniper II, and he may throw it away and buy the quadrajet one, it is such a PITA to get it to fit. Already has a hood dent from the air cleaner stud from the sniper. Not a happy guy.

You really need/want that 2.0" drop base!


Here is the LS5 that hits the hood. The 3/4" spread to square adapter is the main culprit. Even with a BB hood and the flat stock iron intake manifold. That one is 3.5" high, same as an iron SBC, but the BB is 1" higher, and even tho the hood is higher, it does not fit. And he does not want to run a 2.0" hi filter on a 430 HP BB. That would be silly. He is trying to get away from the valve cover filter too, to look stock. The Holley Sniper base does not address that.

You should have about 1" more space with a SBC, but then the std hood is lower, no one knows how much, maybe 1/2-3/4", so you do not wind up with much more room.

Here is the "money shot" from the video.

The fuel fittings are much lower on the Quad Sniper. And the rear fitting has two choices. The air cleaner air intake pipe lands exactly in front of the normal rear fuel return fitting. The Quad version has a second option. He plugs that fitting, and runs the return line out the back optional outlet. You can see that here. This is what makes the air cleaner fit, with it's 1" diameter PCV air inlet pipe intact! The Sniper II does not have a option to run the fuel rearward from that fitting.

 

That's a great suggestion about the Q-jet version of the sniper. I didn't know that was out there.
So.... If I get the long block version of the Blueprint 396......and buy the Sniper Q-jet separately, I could possibly run my factory cast iron intake, or how about a spread bore version of the performer ?
Anyone know anything about Edelbrock's 2101......2104....3706...... or 3701 ? They're all listed for the spread bore / chevy small block AND all have 4.050" pad height.. Which one for low speed torque production?
Edelbrock's 2116 is for the vortec heads.... but the pad height is 4.57"

If I'm thinking correctly, my existing hood clearance is .75" with Q-jet and stock manifold.(3.5" pad height) and twin snorkel air cleaner
Going to the SB Gen1 version of the performer DECREESES my hood clearance by .55" (4.050-3.5 pad ht)
Going to a 2" drop base INCREESES my hood clearance by 1" (2-1)
Net effect is .45" MORE hood clearance than I have now. Should now have 1.2" of hood clearance (.75+.45")

The vortec version of the performer spread bore is .52" higher than the Gen 1 version.... so that would still leave me .68" hood clearance (1.2-.52")

Is the vortec version of the Performer worth trying to get away with 5/8" of hood clearance ?

 

The Sniper I had some fuel inlet options, and one of them was very high, I think that is what the Sniper EFI base is for.
As far as I can tell the Sniper II has no other options on where to put the fuel fittings.

Now another option is to run a one line fuel system, with no return, This eliminates the rear fuel inlet issue.
Run an in-tank LS style pump, with built in pressure regulator/return, and nor return line.

My local Corvette shop refuses to put Sniper IIs on C3s. They go with the 4150 style or Terminator X, which has typical Holley fuel bowl inlet/outlet options.

Many ways to skin the cat!
Good luck!

 

A 2701 (4,25" intake) with a 2.0" drop base is tight, but it works.
A 4.56" LT-1 intake has been tried before with a std hood, and it does not fit.

 

Listen to Leigh. He brings up some great installation points on the Sniper platform. The Holley Sniper Stealth platforms will give you direct fit Holley 4150 style carburetor, but that's not what you have, nor is it the spread bore intake manifold style. If you are trying to stay within stock confines of installation your best bet would be the Sniper Quadrajet - if you are sticking with a spread bore intake style. If you are moving to a square bore style intake (Holley 4150 style), you will have a lot more options. All of the Sniper options except the quadrajet are square bore style throttle bodies.

As Leigh mentioned, the Sniper 2 is the least flexible in terms of C3 bolt on and go for many of the above reasons. Sniper 1 is a little bit more flexible. The stealth is dimensionally the same is a Holley 4150, so it's conversion is the same.

I often advise C3 users of the Sniper platforms - be prepared to depart from stock configurations regarding air cleaners and fuel lines. They all have their issues with physical conversions. You'll have to prioritize parameters of your installation and make it work from there. For example: if you are keeping the spread bore intake design, it really only leaves you with one realistic choice for the Sniper - Q-Jet. Keep in mind that the spread bore intake has a lot LESS overall bolt on options for the SBC than the square bore intakes. However, that may be the easiest to install.

On the flip side, if you are already open to moving onto "more modern technology" one might steer you away from an "old" cast iron intake manifold. Newer aluminum intake manifolds are better designs, lighter, and reasonably priced. So on, and so on...

This is the place to be if you want lots of information before making a large purchase like a crate engine combo.

 

I, personally would be very hesitant to buy a Holley EFI system from a company whose primary business is building engines. The support you will need to get the Sniper system working perfectly might not be there with a shop that builds engines as their primary source of income. You really don't want to have to wait on-line for Holley Tech Support to get back to you either as that can take a while at times. The solution is below in the post.

The Holley Snipers came in several configurations for different applications. The Holley Stealth Sniper looks and fits more like a plain carburetor. It takes the fuel and appears like a Holley Dominator carburetor which helped me with my installation. I am using a factory L88 Hood with the air-box under it and it gets a bit tight using a Edelbrock RPM Air Gap Performer Intake manifold. The system I am running now would not fit under a factory hood, period.
My fuel distribution seems to be balanced as the temperatures from cylinder to cylinder are pretty close using an infra-red thermometer even with a dual plane intake. Throttle body EFI systems are known to have fuel distribution issues on many dual plane Intakes, except for the Edelbrock RPM Air Gap intake. The Edelbrock RPM Air Gap has a divider that goes down the center of the intake and it has a notch milled into it which seems to help the fuel distribution issue.

To eliminate the hood height issue you can use a new, dry (short) single plane intake manifold with injectors and fuel rails. On the top you would use a (short) dry throttle body and with a Holley Terminator you can still have it self-learn and get a very reliable engine. This would allow you all sorts of room on top of the engine and have plenty of hood clearance if you have a small block. Being a fraction of the height of the typical intake manifolds used in the Sniper Installs. Many people have switched to a single plane intake just to be able to close the hood. This might be why the Corvette specialist wants to use the Holley Terminator to control the system because they can give you the benefits of EFI without stacking it on top of the engine. I already have the fuel system and the timing controls of the Sniper System but in the search for more room I think I will stick with Holley and use a Multi-point fuel injection system versus my original Stealth Sniper's throttle body.

One of the most important items related to the Holley Sniper or Sniper 2 systems is the installation and setup of the system. This is where many people run into small issues here and there trying to get the system running well and stable.

There is a company in Melbourne, Florida called efisystempro.com and they sell the Holley EFI systems along with all the needed parts at the best price you can get. The very best part is that efisystempro will provide you with 24 months of Post-Sale SUPPORT. They have a Tier three Holley Technician that works for them and helps their customers with the very best in support. After I ordered the system the Technician called me and asked if I had any questions before I started with the installation. Then he gave me his contact info to allow me to get help right away when I needed it. Wow, what a refreshing approach to doing business. I have learned so much from reading the posts on their website because it has a ton of solutions available for people getting their engines running happily. They have covered 99.5% of the typical issues people have in their postings. This alone is a great help. They sold me my Stealth Sniper and everything including the OEM Fuel Tank module and a complete installation kit for less than $1700 when I had budgeted $2500 for the system. Why would you go anywhere else?

I am buying the next generation of EFI parts for my Holley system from efisystempro.com because I am sure I will need a little help here and there and they have great tech support. If you call them they will help you design a system that works for you and your C3. If you live in Melbourne you would be lucky enough to meet the staff in person, they are very nice people and respond quickly to questions or help.

 

More GREAT information......This forum is wonderfull !
It's looking more and more that I'll just buy the long block from Blueprint, and build up the rest of the system to fit under my hood.
efisystempro will be getting a call from me to see what they can do.

 

I put a GMZZ383 with Vortech heads in my 72. The Professional Products intake from Summit was the lowest pad hgt I could find for a Quadrajet carb.
I tried all different combos of air cleaner elements and bases. I cant remember all of them all but I couldnt find one that would fit under a stock hood and work right. I figured a
LT-1 or L-88 style hood was all that could work. If you find a combo that works with the stock small block hood please let me know and I'll use it too.
Thanks