[Speargun]

After lots of delays due to parts availability, covid, and life in general, I finally got the 535 dropped into my '67 Firebird.

If I knew then, what I know now, I would have only bought the ECU & harness from Edelbrock and sourced everything else myself.
I sent in my (unused) 35 lb/hr injectors and a $100 money order to upgrade to the 60lb/hr injectors, but it took Edelbrock almost a year to get the new injectors to me.
I 'could' have used the throttle body that came with the kit, but didn't think it would flow enough, so I went with a dominator intake.

I've installed quite a few Fitech & Holley systems and this was a little easier. It is most definitely the easiest I've installed that controls timing. I always try to stab the distributor as close as possible to base timing, but this one was ridiculously easy. No rotor phasing, no adjustable rotor, no drilling a cap to check rotor phase; Set crank to show 12* btdc, install dizzy, rotate until rotor points to the #1 stamped on dizzy, snug bolt. I was a whole 2* off. LOL
Personally, I would have preferred that the engine side harness' been a little longer and unterminated. The harness is well made, but a couple of the wires are too long and have to be folded back on itself and one or two are a bit short. They're long enough to reach, but could have been routed a little better if they were longer. They use weatherpack connectors so I'll probably shorten the long one up once I'm sure they are going to stay where they are.

PROBLEMS:
I had no spark when I first tried to start the engine so I checked voltage, disconnected the MSD 6, unplugged, checked for bent pins or bad connections & reconnected everything, checked harness continuity, said lots of bad works, threw tools, etc.... LOL
At some point over the weekend, I swapped out the 4500 Throttle body for the 4150 on an adapter plate to rule that out. After all of that, I finally got the engine started, dialed in the base timing, idle, etc., let it warm up to 200*, then shut it down to cool overnight.
The next day, I re-torqued the heads and swapped the 4500 throttle body back on but it was showing that I was only getting 38% throttle and a max of 1.5 volts on the power & feed wires. Fast forward to many hours, and bad words, later I discovered that the problem was THE MAP SENSOR! Apparently, the new ACDelco MAP sensor was bad and caused the ECU to freak out. As soon as I unplugged it, the TPS voltage shot up to normal and the engine fired right up. I pulled the MAP sensor off of the 4150 and put it on the 4500. Now everything is good in the world again.

Other than that, I haven't had any other issues with the ProFlo4 system. I wish it had tuning software like the Holley systems do for timing and fuel maps and it would be nice to be able to lay out the gauge display how I want, but overall (so far), it seems to be a good system.


INSTALL SUGGESTIONS:
If you are going to install one of these (or pretty much any EFI) systems, I recommend that you install a relay going to your fuel pump and a relay on the pink ignition wire with power coming directly from the battery.


Aluminum IA block
10.8:1 SCR, 8.0:1 DCR
HR 660/629 252/262 @ .050
Speedmaster 72cc w/2.19/1.77 valves & CNC ported to 340cfm
Super Victor EFI intake, port matched to heads
Accel 4500 throttle body
60 lb/hr injectors
Dougs headers


The plan was for this engine to be a dependable, N/A, street engine so I'm not trying to eek out every ounce of hp/tq I can.


As expected, things don't always work out as well in real life as they do on paper and now I have an issue with hood clearance. Even with a 4" cowl induction hood, I'm not going to have room for more than a (maybe) 2" tall air cleaner. This got me thinking about using an LS type throttle body.

I've seen a few setups I like that use a Holley LS high ram top adapted to a Pontiac intake (why isn't Holley producing an intake like this for Pontiac?!!) and Luhn's EFI conversion from the old Offy 2x4 intakes, but both are pricey. I just saw that there is a new LS throttle body top for the Gutsram intake, but I think that would end up being even taller than what I have. (Does anyone have a measurement?)
Right now I'm thinking about using a 4500 to LS 90* elbow pointed to the rear so it pulls fresh air from the cowl. Since the car will be street driven regularly, I don't want to go too large on the throttle body so it's squirrely off idle, but I also don't want to choke it out too much for those times when I take it to the top end.
I don't know much about LS throttle bodies and everything I've read has been geared towards either stockish small cube or all out, boosted, race engines.

What size TB would you recommend for this application?

[HWYSTR455]

Sadly, you will have to experiment, but fairly certain a 102/103 would be in order.

You can tune out any negative drivability issues, and/or use a progressive arm.


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