71bbc

Hi...back in 2016 I restored a 71BB, with whatever upgrades I could to make it more enjoyable/drivable back then. I did a list of mods and later I figured how good most of them are, except one thing...HOLLEY SNIPER EFI.
Car starts, runs OK etc. no problem. There are some issues inherent with design of this unit, combined with factory BB hood clearance. Electromagnetic Interference (EMI) can't be eliminated apparently (I did everything possible ), Edelbrock torquer II, erratic operation of IAC valve and placement of IAT sensor inside the TB (Heat soaking) are bad decisions from Holley. These combined altogether, concern me and kill my mood any time I go to drive it, specially in summer time.
Now, I'm not here to ask for help fixing all these, as I did anything possible to help the situation. I started to gather info on possibility of managing this MKIV BB with adding a 24X crank, 1X cam and a 411 ECM from gen III LS family. So far, I figured how to add CKP and CMP using misc. GEN V and VI BB, and I can eliminate distributor and use COP like LSs do. Last and most important part of this project will be finding an affordable way to squeeze an MPFI intake under that original hood (No I'm not planning to get a L88 hood) that gives me a front or side opening for a throttle body. I found only one guy made something using lower plenum of L29 454 with 2 TBs in some posts dated back to 2006 and the thread died shortly, no feedback found on how it worked (or still works).
I'd like to know if anyone can help me with tips on details or source/fabricate something to works in my situation. I can TIG weld aluminum and have typical home shop setup. I know there are some places build custom intakes, but they want arm and leg for that...probably more than what my whole setup worth.
Also, if anyone has any experience with L29 intake (or any other possibilities), it's dimension or any way to modify it or make it shorter to fit in there, it'd be sweet. That intake has long runners designed for low end torque which is good. Thanks.

zwede

I know you said no L88 hood, but it does make things a lot easier...

roscobbc

Have you considered sourcing an Edelbrock Proflo system? seemingly a very comprehensive piece of kit......however it still leaves you with the inlet manifold height issue - what if you 'junk' the inlet than comes with the kit and utilise your Torker 11 manifold - the Torker may well lose out in performance compared with the one supplied with Edelbrocks kit and presumable you'd need to resolve the lack of injector ports.......but its a potential option.

zwede

I suspect the Torker II is the cause of his problems now and would also screw up MPFI. Very short runners and small plenum so uneven air distribution as well as fuel robbing. Fuel can be pushed back into the plenum during cam overlap and then another cylinder takes it. Modern MPFI EFI will let you time the injector pulse which helps greatly but the short runner Torker II might be too much.

I wanted to put the EFI under a stock BB hood myself but after a lot of measuring I gave up. The only way I could find to make it happen was a L88 hood. The L88 hood is 2" taller than the BB hood.

Maybe a custom sheet metal intake with the throttle body in the rear and Coil-near-plug since there'd be no room for a distributor would work. But that was way more involved than I wanted to get.

1971corvette

Well if you end up needing any mill work done for injector port locations I could possible help you.
All locations & angles would have to be your responsibility.

Can't help you on clearance, I have a small block & a TPIS mini ram that I would like to get setup
and installed within the next 500 years = get that numbers matching block out of there before I destroy
it get my balanced 69 block / aluminum head motor in it's place.

wwiiavfan

The pro-flo is available with a front mounted throttle body but not sure if the overall is low enough to fit under a stock hood.

71bbc

Per edelbrock, that pro-flow setup is 10” tall across. Haven’t measured anything yet, but that intake looks pretty tall to me, especially once you add TB and air intake hose, it probably gets worse. Now, I like the idea of getting air from under the windshield area. I’m planning to get rid of distributor anyway, I’d say there should be enough room where dizzy is to add a TB and some sort of fabrication for a small filter there.
there are 2 possibilities I’m interested in… either ramjet 502 lower plenum or mercruiser crossram lower plenum to fabricate something to cover it. Not sure how it’ll perform. Just an idea. Especially mercruiser plenum interests me, as it has more runner length, but looks somewhat tall also already. What you think…