View Full Version : 425 Inlet manifold part number 1370316 [or 8] B

Nick Stratta
12-22-2003, 09:16 AM

Can you please help me. I am rebuilding my dual qual 425 Super Wildcat. It has an inlet manifold with the part number 1370316 [or 8] B on it.

Can anybody idenitfy it for me please?

Secondy is it any good for a low rpm torquemonster engine?

By the way I thought you might like to know it is chromed, as are all the other accessory parts I got with the engine, whcih was painted red. Could have been a seventies custom job though!

Dr. Frankenbuick
12-23-2003, 05:26 AM
That # is for a stock Buick 2x4 425 manifold from 1965 or 1966. Anything that will put more air fuel mixture in the cylinders at a given rpm will help you out, but also needs a strong vacuum signal. These manifolds worked well with the stock engine, but take some practice tuning.

Nick Stratta
12-24-2003, 03:49 AM
Hi Dr Frankenbuick!

Thanks for the reply - I guess I should be OK to use this then since I'm not building a high rpm engine and am on a bit of a budget. I plan to use rebuilt heads with standard valve size a reasonable cam to improve the low end and an HEI.

Please tell me more about the 'practiced tuning'.

Many thanks

12-25-2003, 12:33 AM

# is definately a 65-66 425 2-4 manifold.

It will work very good on your 65. do you have the orig. carters for it?

They would be the best and easiest to set up and tune.
I have run this same setup on my 65 GS, 4 speed Conv. for the past 33 years with NO problems.

There is nothing like an 8 barrel nailhead with all 8 wide open.

Best way i've found to tune is to disconnect the front carb throttle linkage and set the REAR carb.air , fuel mix, idle, then adjust the front throttle linkage per the factory specs.

Nick Stratta
12-28-2003, 03:10 PM

Many thanks. Yes I do have the 2 Carter AFBs for it. - Looking foward to getting it running and with all 8 barrells roaring!!

Thanks for the advice abotu setting up the carbs.

33 years - wow - you must have some experience!
Did you see my post on what cam grind / heads/ dizzy choice should I go for? Do youhave anything to offer?

It's the cam I'm having the most difficulty with - I want to retain the low rpm torque of the Nailhead but make the idle more noticeable and more lumpy. I still want to have all the power there at just off idle and some way into the mid range - I'm not going to run this engine full on for a long period - probably up to about 4000 revs max. I'm not sure what to go for to retain all the low reve torque the Nailhead has and boost it some more. Some people advise on a standard grind, others an RV cam, some a higher lift, others the Postons NH400 cam or the NH 300 cam.

The one thinkI have noticed is that the more radical the cam gets, the higher the idle point goes up. I think stock is 500 prm, the NH300 is 650-700 rpm and the NH400 is 900 prm. I'm keen to reain a low idle speed.

Do you have any wisdom to add please?