r90camarors

Well, as some of you know, I have recently swapped from a spreadbore performer style intake to a squarebore edelbrock rpm airgap intake and Crane 1.6 aluminum roller rockers.

First problem with the squarbore is that the holley 670 bore's overhang the plenum of the intake. Not a big deal as holley makes an inch adapter plate.
The adapter however, appears to be rather restrictive as the bores obviously have been moved in to conform to the intake opening. The adapter also moves the TBI foward, not too unlike the positioning of the pro-jection intake. The adapter is also cast as far as the bores go, and needed a little gringing in a few places. Also, I need to fab a new throttle cable bracket, as the cable is a little more than an inch too short in it's current position.
So if you have the option, I would recommend a spreadbore intake (rpm airgap for vortec only comes squarebore ), as you can make you own adapter for cheap, as I did with the old intake.

Also, even without the adapter plate, I am rather confident the hood would not clear the injector pod. As it stands now with the adapter plate, the injector pod sits about an inch higher then the firewall. I am currently waiting for my 3"cowl to arrive..

The engine sounds really nice, and has excellent throttle responce at idle, though it still surges. Tomorrow I am going to try to use winaldl as a way to guage my 0-80mph and set my base timing. It's gonna be a lot of fun with the turtle 160 baud rate.....

Pablo

iTrader: (1)

nice, im sure youll get a nice gain from that

as far as the adapter plate, I bought one from turbo city for my original little TBI which fits fine on the stock manifold with just a little notch, for the big tbi i took a grinder to the plate (made of steel so it took FOREVER) and matched it but angled it inward to the match the manifold opening. It works pretty well and is centered. Didnt have to do anything to the linkage its like stock

r90camarors

We were thinking about doing the same thing as far as boring the adapter at an angle. I may still try that, as the holley adapter has the tbi so far foward, not only do the sides angle in, the front does as well. I really wish I would have taken a pic to show. Interestingly enough though, the adapter is an inch tall, however, the underside is open, other than a 1/4" part that the tbi sits on. In other words, there is a good sized gap between the divider plate in the intake and the center of the bores on the adapter plate.
I don't know if this is good or bad.....I would imagine it would cause turbulance, however, it could also allow each cylinder more air.
I guess we'll find out when I run her next time.
Hopefully I'll do the WOT mod you discovered as well pablo

dimented24x7

iTrader: (2)

With the holley adapter, the tbi can be also mounted toward teh back of the intake. This helps with hood clearences, as in my case, but it created clearence probs with the dist. As for the cables, it may be easier to get different cables. I was in the same boat, i had to resize the tv cable and the throttle cable was a total loss. I ended up getting the locar throttle cable and just using the cable itself. I threaded the locar cable into the housing of my stock cable and used the locar adjustable connector. Another nice thing is that the locar connector used a ball mount so i was able to move my throttle cable to the side where it should be so now it lines up with the cable housing rather then at an angle, not to mention that its fully adjustable. Since you have a manual, getting the lokar cable would probably be your best bet. Edlebrock also makes a descent adjustable bracket to mount up the cables. It has the same configuration as the stock one but the mounts can be moved forward and back. I ahve one but imj not sure exacly how well it will work since never tried it.


Not entirely related but ive noticed that the holley stuff in no way shape or form is ment for use with the stock components. I had their adapter plate with the stock tbi and the angles for the tv cable slightly different. Didnt seem like a big deal but since the line pressures where different at part throttle the trans didnt really shift right. With the holley tbi, the location of the mount for the tv cable is lower to compensate for this so the line pressures will be correct. Because of this, all the frictions in my trans are trashed and now it slips like crazy. Yet another reason why i wont ever use holley parts again. They just have to be different...

r90camarors

Yeah, I was thinking about turning the adapter around backwards like you said, but it would have required drilling new holes as well unless I wanted to turn the tbi around as well. As it was, I had dremel the two rear bolt areas so my braided fuel fittings would fit in there.
As far as the throttle bracket goes, for the time being I used the cruise control slot and bent the bracket a little. It is flimsy though, as it only has one bolt holding it in place (I cut a lot off of the bracket when I did my engine swap to make it work).
On the good side of things....I got the Cevini 3" cowl today and it fits like a dream. Took maybe 15 minutes to swap the latch and spring over, and line her up.

Pablo

iTrader: (1)

Yep i know what the adapter looks like I ran one for a short time on my engine before i switched to the centered adapter. I think its a crappy design

va454ss

iTrader: (1)

So, who makes an adapter that centers the TB over the intake manifold?

I also am using the Holley adapter on an Air Gap manifold and questioned how well it would work.

I am also using a 1 inch phenolic spacer between the adapter and the TB and wondered if it would be beneficial to remove the divider in both the adapter and the spacer.