'73 Throttle Body Question

jdogg · 02-03-2003, 01:05 PM

I seem to remember a post at one time that stated the throttle body off a '73 Djet 2.0 was better than than the other throtlle bodies used. Is this true? Why?
I have a '74 2.0 and access to a '73 2.0 throttle body, and wondered if it is a worthwhile swap. Anything I should be concerned with - any specific tuning difficulties?

Bleyseng · Bleyseng's Garage

The difference is the 74 doesn't have the port for the vacuum advance hose. That is a nice feature that you can add to the latter TB's. Some early 73 TB's don't have the return spring on 'em which I don't like.
The hooking up of the vacuum advance gives you alittle better acceleration, (very small).
Geoff

jdogg · 02-03-2003, 01:57 PM

Now, where does this hook up to, the bell on the end of the vac advance canister at the distributor, the one that is normally just capped off?

jdogg · 02-03-2003, 02:24 PM

Yeah, Geoff, I actually went out ot the garage and looked at it, I see what you mean about the vacuum advance. So other than that, the throttle bodies are the same? same bore, etc.?

bowlsby · 02-03-2003, 02:55 PM

Don't bother with this 'upgrade'. It doesn't make that much difference.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Yes, other than that they are the same. Early-early 73s did not have the extra return spring wrapped around the throttle shaft, they had a simple one-piece bellcrank.

Supposedly the vacuum advance has more effect on freeway MPG and engine temps than on acceleration. It should only have an effect when the throttle is open a very small amount.

--DD

Bleyseng · Bleyseng's Garage

Actually, there is several degrees of extra advance between 1500and 3000 rpms using the vacuum adv. Is it earthshaking, h*ll no but it can be felt. You feel it when coming off a closed throttle when crusing and you give it more gas to accelerate. I wouldn't pay a bunch of money for a 73 TB to do this. Just get the proper size tubing, drill a hole 1/4 inch deep into the TB in the right location. Drill another hole with the smallest bit you find in a bit set. Tap in a 3/4" piece of the tubing and knurl the metal around the tubing to set it. Hook it all up.
Geoff