Holley 4160 set-up

[85GT5spd]

I have and 85GT I acquired with no motor or trans. I'm installing an 5.0 originally out of and '88 GT. I'll be running a 4160 Holley. What are some good baseline settings for main jets, power valves, squirters and possibly secondary springs? I looking for decent fuel economy and good drivability more so than all-out power. Out of curiosity, how was the original 4180 carb set-up for these cars? Thanks.

[Walking-Tall]

You tell me what LIST # Holley 4160 you're going to be running, and I'll relay what all should be in it for what you're looking for... including the engine's camshaft's intake duration @ 0.050"...
Forget about the original 4180... you'll only get confusion and potential brain implosion trying to understand... if you don't have to, don't go anywhere near one.

[85GT5spd]

9834-3. It has 68 main jets in it. I'm thinking of start with something smaller, like 64s for what I'm after. The cam is the stock HO cam for 1988. I'll have to dig for the specs because they changed slightly through the '87-'93 era IIRC.

[Walking-Tall]

The #68 jets in it, which are stock, are probably due to larger than usual (0.028") primary main air bleeds, and/or smaller than usual (0.046") power valve channel restrictions, both of which are common in 600 vacuum secondary Holley carburetors. I'd leave the main jets alone. Changes that'd be beneficial would be to toss the heavy black secondary diaphragm spring and install a purple one, and install the green accelerator pump cam. The original 6.5"Hg power valve and 0.031" accelerator pump shooter should work real good.
As for further in depth calibration for really dialing it in... stock/mild camshaft calls for 0.026" primary idle feed restrictions, and beginning with 0.070" primary idle air bleeds, and especially with a quicker opening secondary spring, 0.028" secondary idle air bleeds.

[85GT5spd]

Thanks!

[85GTGuy]

Out of curiosity, how was the original 4180 carb set-up for these cars? Thanks.

From what I've read, in at least one case, the stock main jets on a 4180C from an 85 GT were 64's. Also, someone here said their 85 Capri came with 61's. But he said it ran a lot better after he upped them to 63's.

You tell me what LIST # Holley 4160 you're going to be running, and I'll relay what all should be in it for what you're looking for... including the engine's camshaft's intake duration @ 0.050"...

Also read that an 88 GT's cam should have 266 degrees of duration on both the intake and exhaust.

[Walking-Tall]

Also read that an 88 GT's cam should have 266 degrees of duration on both the intake and exhaust.[/QUOTE]

Yes, that's gross duration, 266-degrees... meaningless to sizing of idle feed restrictions for other/bigger camshafts as to duration @ 0.050"... regardless, with a 600 Holley, for stock/mild intake duration @ 0.050", 0.026" primary idle feed restrictions in a 600 is what's needed...

[85GTGuy]

Yes, that's gross duration, 266-degrees... meaningless to sizing of idle feed restrictions for other/bigger camshafts as to duration @ 0.050"... regardless, with a 600 Holley, for stock/mild intake duration @ 0.050", 0.026" primary idle feed restrictions in a 600 is what's needed...

Gotcha.... thanks for the explanation.