396 Chevy combo......

Adger Smith · 06-05-2007, 11:55 AM

Just checked the NHRA specs (1969 396 vs 1970 402) & it looks like the 401 alum. head gets a tighter chamber in both the 402 & the 396 @ 103.3 On the other hand the iron 396 is @ 104.9 vs the 402 iron @ 106.9.
Dome on the 396 is 40.05 @ .361 ht Vs the 402 with 39.53 @ .344 ht. That was probably done to equalize the difference in bore vol.(CC).
The 396 ex is 1.845, in alum & 1.725 in iron vs the 402 @ 1.885 in iron and alum.
It also looks like the 402 gets to use a better manifold than the original pancake version. I'm not real familar with the manifols esp. the 3967474, but it seems like the 402 & 396 would be at least equal in that area.
You need to check the NHRA Classification guide for the HP. There are some differences between bodies & stick vs auto in the 402 vs 396.
good luck hope this helped
DISCLAIMER: all numbers are form NHRA Tech Specs. I'm not responsible for type-o's or numbers that are transposed. I am responsible for my opinions.

Adger Smith

06-05-2007, 11:55 AM	#9
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Just checked the NHRA specs (1969 396 vs 1970 402) & it looks like the 401 alum. head gets a tighter chamber in both the 402 & the 396 @ 103.3 On the other hand the iron 396 is @ 104.9 vs the 402 iron @ 106.9. Dome on the 396 is 40.05 @ .361 ht Vs the 402 with 39.53 @ .344 ht. That was probably done to equalize the difference in bore vol.(CC). The 396 ex is 1.845, in alum & 1.725 in iron vs the 402 @ 1.885 in iron and alum. It also looks like the 402 gets to use a better manifold than the original pancake version. I'm not real familar with the manifols esp. the 3967474, but it seems like the 402 & 396 would be at least equal in that area. You need to check the NHRA Classification guide for the HP. There are some differences between bodies & stick vs auto in the 402 vs 396. good luck hope this helped DISCLAIMER: all numbers are form NHRA Tech Specs. I'm not responsible for type-o's or numbers that are transposed. I am responsible for my opinions. Adger Smith __________________ Adger Smith (Former SS)