Inliners International Forums General Discussion Engines Replace 2SE with 2G on 84 integral head 250?

Hello,

A friend of my son has an 84 pickup with the integral head 250 that came stock with the 2SE. The carb is leaking and needs a rebuild. I am not familiar with this carb or the integral head it sits on. Is this carb worth rebuilding or should we toss it aside for something better? Would a 2G bolt on and work better? Can anyone make some good suggestions or point me in the right direction?

Thanks a lot,

Scott M

The 2SE is a progressive 2bbl, 1/2 of a Quadrajet 4bbl, it has a primary and secondary barrel. The 2G is a straight 2bbl, it runs on both barrels all the time. The 2G also has a different bolt pattern requiring an adapter to bolt in place of the 2SE. You would probably lose some mpg with the 2G, and it would require tuning for you 250.

All carbs require maintenance with age. Depending on where it is leaking it may just be a matter of buying a carb kit and cleaning, adjusting the carb. If the leakage is around the throttle shafts then it needs a rebuild. I'd check with your friendly local auto parts store (FLAPS). I just checked NAPA and their showing it's available $559 - Ouch. NAPA also shows 2 dz different carb numbers that their rebuild replaces, that's not good. If that is the original carb, considering age, that's in doubt. I'd keep the old carb core is only $12. The rebuild is probably generic and the old carb (if original) would help tune the rebuild.

Another alternative would be to contact Stovebolt Engineering they sell a Holly/Weber kit that is a progrssive 2 bbl. Their kit is a very poplar kit for the early 235/230/250. The kit would not bolt to your integral head as it is meant as a replacement for a 1bbl, and the bolt pattern on the carbs is also different. Call Tom Langdon at Stovebolt or Patricks they may have another alternative you should be able to find their links on the left column.

Larry

Thanks for the reply Larry. The kid is on a low budget, meaning I am probably taking on another charity case, but what the hey. The lack of funds was why I was looking at maybe going with a 2g. I guess I will try a rebuild kit on the 2SE first. I understand this carb works real well on a smaller engine in a light car where you can run on the primary most of the time. The kid tells me he is in the secondary a lot just to keep up with traffic.

Scott.

Scott, Forgot to Welcome you aboard!

Also forgot to mention the Holly/Weber is a bit smaller cfm carb, the secondary is smaller. The kits sell for about $80.

Being in the secondary could be several problems. You don't mention what the 250 is in. If it is a truck it could be rear axle ratio. Trucks usually have a high ratio 3.73, 4.10, 4.56, not good for cruising the freeway. It could be the kid is trying to get more out of the 250 than he should or it's due for good tune up. I'm not familiar with the integral head motor. It should have an HEI distributor which is a plus. There have been reports on the boards that the integral heads have a tendency to crack.

Larry

It's in a 84 pickup. It still kas all the emissions plumbing, but it looks to be in poor repair. I think the first item will be to fix any vacume leaks and get things in good tune, then maybe put a kit in the carb.

Scott.

That's a good start.

The 2SE looks like half a Quadrajet. I don't know how close it's tune is that of a Quadrajet. My 68 C20, with 350 and a Quadrajet the secondaries come in at 2500 rpm, and the mpg drop big time. I've got 3.73 gears in the 68 and at 2500, I'm doing about 55 mph. Hope that helps.

Larry

Scott,
I too, am the proud owner of the dreaded integral head with the Rochester Varajet, 2SE carb. 1979 Chevy pickup.
I have spoken with Mr. Langdon regarding putting the Holley/Weber on my head. It will not work without an adapter as Mr. Griffin stated. You would have to make or have made, an adapter. The 2 SE is good carb when it is functioning correctly. The secondary has a good size opening. Rebuild kits seems to be plentiful, but if you go that route be sure to provide all the number from the 2SE when ordering. Try to avoid the kit(s) that give you a handful of float bowl gaskets from which to choose. Get the kit specific to that carb. Question, do you have SMOG inspections for registration? If so does it have to be original equipment?
If it does not have to be OE to pass then you have options. The reason I ask, is a "regular" 250 head will bolt right onto the 250 block with the integral head. Same lifters, same pushrods, same headbolts, same thermostat housing, water neck. Then you have many options. You can get 1bbl manifolds, and exhaust manifolds economically and use a 2 bbl adapter. If you choose to hang with the 2SE, your plan to check all the vacuum hoses, and there are a bunch, is a good place to start.
I have put the "regular" 250 head on mine with success so if I can help please ask.
Ken

Thanks for the reply Ken,

This truck belongs to a friend of my son. He is on a low budget so we will probably keep the intgral heead and 2SE as long as there are no cracks in the intake. I took a glance at the emmissions plumbing and it is in bad shape. I'm sure this is his main issue. There is no emmissions testing here; not even a yearly safety inspection.
The cheapest route will probably be to remove the emmissions stuff as it is not working anyway, then put a high quality kit in the carb. I was hoping a 2G would bolt up since this would be a nice performance upgrade and I have had good luck with the 2G on some other cars.

Best regards,
Scott.

A major source of vacuum leak on this engine is the exhaust manifold gasket to intake. with the carb off you can see what looks like a tin can lid (circular pattern), this is part of the gasket, transfers heat from exhaust to intake. when it burns or rusts thru you have vacuum leak (full time EGR!).

Thats a great tip! I've worked on quite a few slant sixes and 300ci fords, but I'm just not familiar the chevys.

Thanks,

Scott.