New - Lots of Questions. Help me understand S&SS

[LemonWedge]

Originally Posted by Steve Stasko

I believe Greg Gay runs the 400-4 barrel in his Mirada out here on the east coast. It is not a bad combo. I looked at it as an alternative to the boat anchor I am putting in my 66 Dodge. I would look at the 73 400/265. It is rated at 20 hp less than the 72 motor. NHRA rates the 72 at 330 hp and the 73 at 310. The Thermoquad is a great carb, and a lot of people forget that it was originally designed by Carter as a race carb. Not sure how heavy your car is, but the 73 motor at 3735 puts you in GT/LA. 11.05 index, and no cage needed.

Another to think about in GT is the 70 Chrysler 440/350. It is allowed the same bigger Carter as the 375 hp motor, but you must claim it as a Chrysler. The Dodge/Plymouth combo uses the baby Holley. That combo puts you in some tough classes though (GT/H-ish) at a decent weight (3500-ish?)

As for the 440 low deck, it is probably a 440 combo using a 400 block with the 440 rotating assembly stuffed in it. The downside of this is you will need a short custom piston. Not sure how much money you are wanting to spend, but that option adds up fast. Most all 440 combos are going to put you in a higher GT class. GT/A-K require a cage. GT/L and down do not.

Im extremely familiar with all 400-block combos. Built and raced more than a few of them. Ran a 3.75 stroke 451 with Stealth heads for a decade. Loved that thing. Current motor is the same crank & pistons, had the crank offset ground to 3.875, utilizing a 6.70 BBC rod to land the piston at zero on a .020 decked 400 block. At .040 over, it makes 468 cubes.

I didn?t think a 3.75 stroke 400 block would be legal though. It runs a different piston pin ht than a 440. Or or shorter rod in some cases. Typically an .990 pin. Either way, it’s a lighter rotating assembly than in a 440 block. The block itself is lighter too. If it is legal, why would anyone ever run an RB block?!