slot on intake in front of carb?

[sbc10guy]

I just took my old 2 barrel off my 400 smallblock and it had an adapter on the bottom because it has an old cast iron intake for a 4 barrel. When i got it off there is a slot between the carb and the carb stud holes. The slot has holes that go down on each side and my new edelbrock doesnt cover this slot. What should i do about it? Thanks

[yuccales]

You can get a thin metal gasket (that does not have the holes or slot) that goes between the intake and carb gasket. Those two holes in the intake send heat under the carb from the crossover port. If your changing intakes and don't want to have heat under the carb, you can also get intake gaskets with block off plates. I hope I'm understanding your question. Others will chime in soon.

[sbc10guy]

Yah i just found a site that showed the plate that goes under the carb and blocks this slot off. My new question is can i just black off the 2 holes and jb weld the slot in so that its flat and I don't have to buy anything else?

[yuccales]

Originally Posted by sbc10guy

Yah i just found a site that showed the plate that goes under the carb and blocks this slot off. My new question is can i just black off the 2 holes and jb weld the slot in so that its flat and I don't have to buy anything else?

As for using JB, I'm not sure if you can use it for that. If you have headers or your heat riser is froze up (as most are) I don't think that much exhaust is going through the crossover anyway, so you may not have to do anything with those holes.

[sbc10guy]

I ended up pounding an alan head bolt in each hole and they fit tight and plugged them, im going to call that good enough. When i first got the truck a gasket was covering the slot and it blew out while doing a burnout so i don't know if theres a lot of pressure or what exactly but i'm just hoping for the best here.

[68Gold/white]

Those 2 holes connect into the exhaust crossover under the intake plenum. THe "old timey" engineering was to get heat to the carb on cold starts. It did/does work, but corrodes the base plate of the carb. I think 68 or 69 was the last year for that ordeal.

I can't remember what size for sure, but I tapped those holes and used pipe plugs once and I think I used the threaded section of a couple of bolts. I slotted the ends to screw them into the threaded holes. I masked off the intake plenum holes while tapping the holes and vacuumed the tap filings from inside the hole. Sounds risky getting a filing in the exhaust crossover. I don't think that what little I tapped, that there was carbon catching the filings that stayed in the hole.

If you tap and plug the holes, you won't need a plate.

[davepl]

People do plug them, and its very common to block off the exhaust crossover ports at the heads, but it will mess up drivability in the cold. The intent is to speed up warming of the carb, which it does nicely. But you do need the proper tin gasket or the hot exhaust will just burn through the regular gasket.

The best option is to do what the factory did, which is to run the right gasket setup. Failing that, you can block it in any number of methods, some of which are described above... but it was there for a purpose, and you'll lose that "feature".

I'm a big fan of cars starting and driving in the cold like they did when they were new, but 40 years later most have been "improved" so much it takes two feet and a little luck to drive them...

[sbc10guy]

I did end up finding info on that setup and it would be fine but not for the new edelbrock carb. I ended up finding out the butterflies hit and the throttle wouldn't completely open because of the small holes in the intake so i just ordered a new aluminum one anyway. Oh well i guess, its all a learning experience.