I was wondering what manifold to put into my engine (305 L03) that will complement the Holley 670 TBI? Is the Edelbrock Performer any good or is there better? Well what are all the choices?

 

I would say it is best to make an adapter plate out of thin plate like mine and mount it any a manifold of your choice. All the TBI manifolds seemed to restrictive for any performance apps. It is easy and cheap to make a plate out of say 1/4" alum plate. The adapter holly sells is crap. Hope this helps.

 

I would adapt it to a single plane manifold of your choice.

 

Well what are some of you guys running on? Oh and on single-plane/dual-plane, which is better and why?

 

I would never run a single plane unless your only running at the track, I have two buddys that run 11s in their big block cars with dual planes. I would say a single plane is inferior to a dual plane below 3000 rpm, but from then on it makes more power. The mainfold of choice for me is the edelbrock performer rpm air-gap.
good for 1500 - 6500 rpm.

 

the fastest TBI times have been with single planes. 13.9 on a 305 and 13.5 on a 350. no nos or chargers. The 305 had a holley/weiand 7525 and the 350 had a edelbrock Torker.

Try the holley/weiand 7547. Its under $100.

Its been rumored that the single plane is better for TBI fuel distribution than a carb dual plane, but that hasn't been confirmed.

 

https://www.thirdgen.org/techbb2/sho...threadid=99767

 

Those times don't seem very impressive, In my truck i'm running high 13s. this is on a stock (hogged-out) 350 tbi. I'm sure my motor could go really low 13s in a car.

 

Who's got the 13.9?

 

palric

 

Hey Taz, think you could get palric to post specs on his engine or send me to a post where he talks about it?

Oh and on the Holley site, the Weiand Stealth #7547 states, "Chevrolet 262, 283, 305, 327, 350, 400 V8
1957-86 All Models; 1987-Later w/Aluminum Heads." Doesn't the L03 305's (mine's an '88) have cast iron heads? What do I need to do to this intake to fit it on? If I get the Holley 670 TBI and this intake and a 14X3 cleaner, will it all fit under the stock hood?

 

You need the intake pattern that works with the 87-95 pattern. The pattern on that intake has all the intake bolts at the same angle but our's have the two middle bolts more upright. You would need to elongate the holes on the intake to make it fit. Do you need to be emissions compatible? If so, why not consider the 7525? It has EGR. Both intakes will fit with a 14x3

 

Actually, I'm in the one of few counties of MD that does not require emissions inspection!

 

Hey Low could you tell us how you built your TBI adapter?

 

The adapter was pretty simple to make, using only hand tools.
I got 1/4 alum plate from the local steel scrap yard ($2), then measured the size of the intake (carb) bolts to get the overall size and then drilled them a little big to give me some play. I used an angle grinder and vise to get the overall shape (6"*6-1/2", this you could get done at the steel yard. then I placed the TBI on the plate where I wanted it ( I would suggest a little bit towards the front) and marked the holes. Then drilled and tapped the threads, 17/64" bit and 5/16" tap. When this is done you can bolt the TBI on, then etch the bore holes, and unbolt the TBI. I used a drill and a 1-3/4" hole saw. I drilled the holes a little big for more flow, then I put a grinding bit on my drill and worked the bottom of the throttle body to match the holes in the plate, and to give the plate nice large opening on the bottom side of it, so that the air flow wouldn't experience the turbulence of going accross a 90 deg angle( I tried to make mine more like 45 deg). I had to also do some rotary grinding to the intake where the throttle bores come through,( the intake isn't as wide as the TBI). All said it cost me $2 and about 3 hours in my garage, also it is low-pro for hood clearince. I would strongly suggest loosing your EGR, but it has to be programmed into your prom (motor may work fine without programming - I don't know)