Intake and Carb combo advice

[S.J.SLEEPER]

Originally Posted by The_Bishop

^ This.

I have a crooked knuckle on my right hand thanks to an accel HEI. Long story.

About your choices:

I don't like Holley carbs on drivers. Crappy, leak-prone design that doesn't do part throttle (90% of street driving!) well, always tends to run rich leading to stinky exhaust, fouled plugs and poor mileage unless you spend far, far too much time dicking with it. And when the weather changes it's out of sorts again. For a car that spends a majority of it's time at WOT they're pretty damn good, though.

The new holleys don't have these problems. I do agree with you if your talking about the older models, weather tempermental...blown power valves etc...

I just put on a new holley 750 on a maverick which had the eldebrock performer, ford 302 crate motor. was deadon perfect besides having to adjust idle right outta the box.

Edelbrock carbs are very good though...not knocking them, just making things clear on the holleys.

[BonzoHansen]

My holley works good.

[L695speed]

Originally Posted by S.J.SLEEPER

The new holleys don't have these problems. I do agree with you if your talking about the older models, weather tempermental...blown power valves etc...

I just put on a new holley 750 on a maverick which had the eldebrock performer, ford 302 crate motor. was deadon perfect besides having to adjust idle right outta the box.

Edelbrock carbs are very good though...not knocking them, just making things clear on the holleys.

So its possible the Holley my friend had on his pickup was an older model then. He spoke of having to constantly keep it in tune. If its truly almost a toss up because of the street car nature of the build, I guess I'll go on price and worry about the intricate details when I am ready to squeeze the power out of it. I'd like to get it running and enjoy it for a bit despite the shape off the body. Especially the way the chassis is setup.

[BonzoHansen]

Originally Posted by L695speed

So its possible the Holley my friend had on his pickup was an older model then. He spoke of having to constantly keep it in tune. If its truly almost a toss up because of the street car nature of the build, I guess I'll go on price and worry about the intricate details when I am ready to squeeze the power out of it. I'd like to get it running and enjoy it for a bit despite the shape off the body. Especially the way the chassis is setup.

or perhaps he doesn't know how to tune a carb?

[WildBillyT]

Originally Posted by L695speed

So its possible the Holley my friend had on his pickup was an older model then. He spoke of having to constantly keep it in tune. If its truly almost a toss up because of the street car nature of the build, I guess I'll go on price and worry about the intricate details when I am ready to squeeze the power out of it. I'd like to get it running and enjoy it for a bit despite the shape off the body. Especially the way the chassis is setup.

My holley works great too. Some guys blame timing issues on their carb.

[S.J.SLEEPER]

Originally Posted by WildBillyT

My holley works great too. Some guys blame timing issues on their carb.

[The_Bishop]

I didn't have timing issues after I threw out the POS accel HEI I had. Went to a completely adjustable MSD billet distributor (Not the HEI version) and 6AL box with a nice short curve that started around 14 degrees and ended around 34-36, all in by 3000 or so. (It's been *years* so I might be fuzzy on specifics.)

I had a box-stock 750 vacuum secondary. It was a POS. Hard to get the balance right on the secondaries opening; they were either too damn fast causing a bog or not open fully. Swapped that one out for a 650 double pumper. No bog on WOT, but fun, fun, fun with pig-rich idle and part throttle operation that took a lot of screwing with to get close to right. Got tired of fouling out plugs with that disaster and moved to an Edelbrock 750. Had zero issues. It was almost perfect out of the box.

Holley's don't (or didn't; I haven't messed with a carburetor in a *long* time) handle part throttle transitions well. The power valve is a sledgehammer fix to part throttle transitions; it's on or off and not linear. It was designed as a 'race' carburetor, so part throttle operation was secondary to WOT mixing.

Meanwhile, the Edelbrock is a lot like a Carter AFB, which was an OEM street car carburetor. It was designed with part throttle driveability and economy in mind. It uses a linear needle for low vacuum enrichment, not an on/off valve. By picking the correct needle and spring setup, you can control how fast and how much enrichment you're getting.

Believe me, I used to be able to tune carbs and distributors. I was the go-to guy for it amongst my friends. I have since discovered fuel injection and can now tune without getting my hands dirty, so I'm out of touch with the latest in 'barely controlled leak' design in carburetors these days, and ignition can be controlled in a vastly superior way that doesn't involve vacuum pull offs, weights and springs.

[The_Bishop]

Also, no matter what you're tuning, get a damned wideband. Otherwise you're shooting in the dark. Reading plugs is witchcraft unless you cut the engine off just right and you've seen hundreds of plugs to get an eye for what you should be looking for other than "it's black, so it must be rich" or "it's white so it must be lean."

[L695speed]

Ok guys I get it, either one will do. If it really doesn't matter these days, I'll run with whatever carb fits my budget. I won't run a start retard box because this is a street car, but digging around and your input seems to say to use a 6A or up box with a vac advance distributor. Question is if I should use a stock GM vac advance HEI or use an MSD setup or skip the HEI all together. I will state again, this is no race car, I just want a fast street car. 450 horses is my final target, if I exceed that great. I WILL NOT use an Accel dizzy. Believe me, if I was in the mood to rewire half the car I would have went with the fuel injection, likely LSx. But I will save that swap for another car.

[Slow Z]

I ran a 750 Speed Demon and RPM intake on my old Vortec 350. I run the same carb on my current motor but since I no longer use Vortec heads I run a Professional Products hurricane.

I'm also a huge fan of locking out the timing on just about any car with an aftermarket cam. In my experience it always makes the car idle better, run smoother, and go faster at the track. I have a 10.8:1 SCR motor with a CVR mini-starter and crappy walmart battery and it starts just fine without any sort of start delay even on the hottest of days.

[Paul Huryk]

Holleys offer a lot more adjustability thana Q-jet or edelbrock, but are not for the impatient.

I absolutely despise the 6AL box - had 2 and they both crapped out as did probably 8 of my friends, this was a while ago and hopefully the issues were fixed.

If you want to run 12.0 with your car, it is going to need a power to weight ratio of 8.5 or better to run the 115mph typical of such a run. In a 3500lb car, that is 411hp, in a 3250lb one, 382hp, in a 3000lb one, 353hp. I had run 12.5 at 113mph with the transplanted 350 in my 3500lb third gen, making about 400hp with a 700R4, peak power about 5500rpm. 450hp would push the car easily into the 11's with traction.