First I just want to thank this site and all its users for all the info I'v used in putting my '66 together.And now I need more advice,I'v recently put a stock'78 400sb out of a 4x4 in it and needed a carb so I bought a used tunnel ram,the guy told me the carbs were 600 hollys and the intake is an Elderbrock TR1Y.My question is what all do I have to do to use this on my ca 400? can I just put a cam in it, or do I have to get the motor built? Also I'v heard the stock dist.won't fit what do I have to do in this case?And also can I keep the stock fuelpump?Thanks again in advance.

By the way I forgot come check the ride at http://members.cardomain.com/4speed66

Can you say 'big can of worms'? I would just get a good carb on the stock motor.

Bryce, nice '66. You can run the tunnel ram on your engine - but to get the most out of it you will need much more than a stock 400. Tunnel rams are cool, great visual impact. But even on my 496 BB I run a single four barrel carb, now on a dual plane intake manifold.

Thomas

i have seen and done for myself make the hei's fit behind the tunnel ram.....depending on the intake it may only need a small clearence grind. im on a budget and a lot of my friends are so having the lack of money we have to find ways to make our stuff work ...we just cant drop 150 bucks for a new dist. i even run a hei behind my bbc tunnel ram and that was tougher to do then the sbc.......sbc mostly just require small amount of grinding to get it in on the intake....

other option for budget is go to points....or even dual points........the next step would be a conversion to electronic . take points out.

or just buy a whole new dist.

make the hei fit ( im assuming this is what you was saying stock)

points dist. used real cheap under 25 bucks most give them away.

convert points to electronic

buy all new dist.

cheapest to new.....take a pick...


need to set both carb up the same. same acc. pump cam, same amount of acc. pump movement, same jetting, same squiters, same idle screw settings, same amount of both primary and secondary opening on the throttle shaft. make sure they have the same color secondary spring. others like to run a tube to each carb on the secondary's vacuum pod i have not found the need for this yet. another words they have to be same in every aspect.....the more you pay attention to the small details on getting them the same the better off you will be ....be anal about it....if you just slap them on you will have headaches and this is where some say tunnel ram dont work on the street....because i feel that just slapped them on and expected them to work.....be nal about the setting and dont mess with the idle adjustments til they are connected then you can run just the idle screw off one carb......

I ran an Edelbrock tunnel ram on '70 back in the '90s. No, the stock HEI will not work with that intake manifold... the distributor is too wide. I had to goto a Mallory Unilite when I put that intake on.

Also, 2x600cfm carbs is WAY to much for a 400ci SBC. I think I had like 2 x 350cfm Holleys on a 350 ci.

As many have said, great for looks... but they're a pain to tune correctly... and truth be told, for a street car, there are better performing options.

the fact that two holley 600 carbs are sitting on a tunnel ram just dont mean its to much. the engine is still only seeing 600 cfm when the car is opened up, 300 cfm from the first primary and 300 cfm from the second primary. the vacuum secondarys will open when more is needed. it wouldnt be no different then a 600 double pumper.....if the signal is there to open the secondary's they will crack open ....... granted the engine will not see the whole 1200 cfm but it will use only what it needed.....

i have even ran a tunnel ram on a stock 305 sbc with no more then a 305 comp. cam. 4500 stall and 4.56 gears and the stock advertised 8.2 to 1 comp....the heads just had a 3 angle valve job and better springs and guides cut down...granted the car only ran 13.60's but it didnt sneeze under full throttle..yes the bottom end was soggy but it sure was fun to drive.......the secondarys never fully opened...which was tested with a paper clip located on the vs rod assy. which showed the secondary's just cracking open.....even at the 7000 rpm shift point.

but i would say two 600 double pumpers would be to much.that would be a real pain to tune with that much throttle cracked open at once..that would take a lot of squiter to cover up the would be "dead spot"......

Too large or not... My lesson learned was that the tunnel ram, while great looking, was not a good match for my 100% street 'velle. I would have been MUCH further ahead with a good dual plane, single carb (or EFI) intake. If you're going to run a light car (read: not a stock a chevelle) and most of the operating time will be down the strip balls-to-the-wall WOT racing... then I may consider the tunnel ram. Not on 100% street 4k lb Chevelle. If you do go tunnel ram, just understand up front that tuning is much more complicated... plus all of the work/time/cost for the scoop, new distributor, etc. And the fact that if later change your mind, you now have a big hole in your hood.

thanks guys well I guess I'll think about it a little more..I want to cam the motor anyways just thought I'd try the tunnel on and see if i can get it to work,maby run around a little without a hood till the cops nail me