Installing an Edelbrock Power Package on a Pontiac 455, Pt 2
Last article, we installed the lower half of an Edelbrock Performer RPM Power Package onto our 1969 GTO Judge convertible’s 400 cubic inch engine. The cam and heads bolted on without fanfare. The intake and carb installation went without a hitch as well. That is not to say there were not some issues along the way. To recap the previous article, we wanted to add some power to our GTO without having to drown in the sea of performance parts available these days. So we chose to pick up a complete kit from Edelbrock. The Performer series power package is designed for emissions-controlled vehicles, since our GTO lives in Oklahoma, which has no emission testing, we went for the Performer RPM series Power Package, which yields even more output and has a wider power band for more fun on the street or strip.
Once the cam and heads were installed, the water pump assembly went back on. The intake, which is a Performer RPM design, features provisions for an OE style choke, so an aftermarket carb is a must. We chose the performance matched Edelbrock Performer carb. You should note that this intake DOES NOT fit under a stock TA shaker hood, so keep that in mind should you decide to install this package on a TA with a shaker hood. The intake makes power from 1500-6500 rpm, making a perfect street-performance intake.
Once we had the engine itself all put back together, we went to bolt up the headers. “Not so fast” said the gearhead gods. We missed a little sidenote to the heads in the catalog. The Edelbrock aluminum heads are based on the Ram Air IV design, and have the D-shaped ports. Only Ram Air IV stock manifolds or headers will fit these heads. Since we originally had a set of Ram Air III heads and headers on the car, our headers would not fit. This put a little kink in our plans and stopped us dead in our tracks.
On top of all that, Edelbrock does not make a set of headers that fits these heads. We actually had a bit of difficulty finding a set of headers that would fit our car, with the 400, factory A\C and Ram Air IV heads. Yikes. Hooker headers however, came to the rescue with a set of Super Comp ceramic coated headers. These are the only headers that would fit our application, although, we did have to remove the factory A\C box (we were going to replace it with aftermarket stuff anyways). Once the headers showed up, we still had some issues getting them to fit.
The replacement-style motor mounts had to be trimmed on the passenger side to allow the header to fit to the engine. We also had to dimple the passenger side where it passed over the upper control arm, as it hit it pretty hard. The headers had to be installed from underneath the car, so having a lift handy was a nice thing to have. The driver side was not much better, the headers fit to the engine without dimpling or trimming, but we had to order a mini-starter. The stock full-size starter touched the header, meaning it would not last long and seeing as how the header had to be off the engine to mount the starter, changing it in a parking lot at 2 AM would not be fun.
With the exception of a few setbacks, the install was fairly simple and resulted in more than just a few added ponies. The engine was putting out around 350 horsepower and fun to drive before the Power Package, but now keeping the tires from spinning is a real problem, one that most of us enjoy having. All of this adds up to a seriously simple solution to a complex problem of making performance modifications.
1. When we left off in the last article, the heads and cam were installed and the top end was ready to bolt on. Here is where we discovered a problem. The headers we had were for Ram Air III, the ports and bolts didn’t match up with the new heads.
2. The only set of headers we could find were these (bottom) from Hooker. The large round ports match up the Ram Air IV-based heads.
3. We tried to drop the headers in from the top, but no dice. Even with heads off the engine, they won’t fit.
4. Since Redline Auto Sports has a lift, we lifted the GTO up and slid the headers in from the bottom. This might be a little tricky on jackstands.
5. The other obstacle in the way was the A/C condenser box. We had to remove it in order to clear the passenger side header.
6. We also had to clearance the passenger side motor mounts. The square tabs on either side of the metal mount had to be removed in order for the headers to clear.
7. With that done, the header bolted right up to the heads.
8. The driver side header had its own issues. The stock-style starter fits, but touches the header. This is a bad idea, the starter is not going to last long with this much heat running through it.
9. We went with a mini-starter to alleviate the problem. The GTO is a 4-speed, which causes some fitment issues with most mini-starters, due to the fullsize bellhousing, that does not angle back like an automatic. Here we test fit the starter mount.
10. We had to slightly clearance the mounting block to fit the bellhousing.
11. The original valley pan was cleaned up and reused, then the new intake was dropped on.
12. We used a set of stainless steel intake bolts to set off the engine, why use a bunch of crusty old bolts? These 12-points have a smaller head too, which makes fitting a socket easier.
13. Don’t forget the water neck, heater hose pipes and plugs!
14. We installed carb studs for better holding power and easier installation of the carb.
15. The carb was then bolted down.
16. The completed engine is looking good, but we aren’t done yet.
17. These holes are for additional head cooling, you can either plug them or install pipe fittings and run hoses to the front.
18. The distributor needs stabbed. We had to roll the motor over, so marking the distributor before removal was pointless. Set the motor to TDC on the number one piston and point the rotor to the matching position on the cap. Slide it in.
19. We installed the plugs and wires and plugged in the distributor, ready to run.
20. Breaking in the camshaft is an important step. Fire up the engine and run it at 1500-3000 rpm, slowly accelerating and decelerating the engine for 20-30 minutes. Let the engine cool and then drain the oil and replace it with new. It is important to use high-zinc petroleum based oil for break-in, and not synthetic.
21. All done, the fresh performance mods made a serious impact on the enjoyment factor. Tire smoke comes with ease, and sometimes comes unexpected. Simple, easy and reliable, the Edelbrock Performer RPM Power Package worked out great.
Sources:
Edelbrock
Hooker Headers
https://www.holley.com/products/exhaust/
Red Line Auto Sports
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