clowe1965

Not in a mustang anymore, but I've got a 68 302 with some serious vacuum leak issues. Currently residing on it is a crappy (but cheap) 1985 mustang manifold, two 1" spacers, and an edelbrock 1403 500 cfm 4 barrel. One of the spacers serves to block off the exhaust cross over, and the other is an insulator since the first one is solid aluminum.

I think I have a warped carb flange because I cannot fix the vacuum leaks at all. I've taken it off once and started sanding but I don't think i went down far enough. That being said, here are my two options. Buy a new intake (125) and spacer (40) and sand down the carb more, plus a rebuild kit for the carb since I have to disassemble the base again (50). Second option is to throw the old 2v manifold and carb back on. Downside is it adds close to 20+ lbs, I don't have anything for the heat driven choke, I have to rebuild it, and its going to make less power. Power is not a big deal because its in a 92 ranger which already has traction issues. Upside is its a lot cheaper (20, plus some fix for the choke).

So which one would yall choose? Fix the problematic 4 barrel, or downgrade to the 2v?

rmodel65

i bet its the spacers leaking...honestly id take the carb off and check it with a straight edge before i bought anything. as for size 500cfm is about perfect for a stock motor iirc most 289's had 470cfm carbs

fastbackford351

As far as the choke goes you could hard wire a cable and kick it old school can't you? Bonus points if you do it with an old factory FoMoCo cable.

clowe1965

Yeah I'm not worried about the size, but I will lose power going back to the 2barrel. I know the spacer/spacer gasket is leaking, there's a crack in it where it used to sit on the exhaust crossover. When I'm testing for vacuum leaks though I find that the carb/spacer gasket is leaking more so than the other connection. The only one that doesn't leak is the spacer/manifold gasket.
Can you connect a manual choke to the old 2v carbs? I've never looked into it.

boogerschnot

Why not get a new spacer? They are only 20-30$ at most. Or try using two gaskets instead of one. Thats what I did on my 289. The first gasket wasnt thick enough for a good seal.

TomKat

4 barrel no question

clowe1965

I need a new spacer, but the crack is only at the bottom. Both surfaces are completely flat though, and I still have a leak at the carb/spacer section. At one point I tried one of those 1/4" heat insulating spacers but even that leaked. I'll order a new spacer and try a thicker gasket (3/32 or 1/8 probably) to see what comes of it.

boogerschnot

Like I said use two gaskets and torque it down nicely. Not over tight but with two you should have enough squish to close it up.

clowe1965

Well I got a new spacer, and installed it, with two gaskets on the spacer/spacer setup and one on the carb spacer face but it leaked pretty bad.

I took the carb off and stripped it down then sanded the base with some 320 grit. Took nearly 3 hours of sanding before it appeared to have a level surface all the way around. Put it all back together and put it on the engine, torqued to 18 ft lbs evenly, and it appears that the vacuum leaks are gone. However, the **** car is still skipping.

One idle mixture screw doesn't appear to work properly. I can screw it all the way down and the engine idle barely changes. The driver's side screw causes the engine to stumble when it is screwed all the way in, so maybe my carb is just trashed. Only other thing it could be is I don't have the plug wires routed neatly so the voltage may be jumping. It's a pertronix HEI unit with 7mm accel wires. I'll go neaten those up, but after that I guess I'll get a new carb, give holley a try or an autolite if I can find one. Any idea's?

boogerschnot

Holley is my choice. They are easy to work on, easy to rebuild, and easy to tune with only limited tools. You could probably find a cheap one on craigslist, and a rebuild kit is only $30. Go for something around about the same CFM. 500-600 will work well. Check ebay, you can get a decent carb for around 50-60 dollars, then rebuild it.