Originally Posted by BOBCRMAN@aol.com
1970 396 is actually a 402. 375 hp version is a four bolt block with valve reliefs in the upper cylinder. Heads for 70 are 454 closed chamber. Rectangle port with 2.19 intake and 1.88 exhaust.. These are the rpm version of a big block, stock solid lifter cam will rev to 6500+. 11 to 1 compression. Flat low rise intake manifold. The same as the 70 Corvette. These engines originally had distributors that were modified to have vac advance only in high gear. The Holley carbs, tho the same specs as a 3310- 780 carb were rated for emissions as 450 cfm..
.....and when coupled with a 4 speed or TH400 and some 3.73 gears will plant your butt firmly in your seat if you get it hooked up. The original '65 Vette and Z/15 Chevelle version was rated at 425HP, same intake, cam, compression and very similar heads. GM dropped the HP ratings for NHRA factoring and insurance reasons. A bone stock '69 Chevelle SS with the 375HP, 4 speed and 3.73's would blitz the stock tires in 4th gear at 45 MPH...... I done it.