M1 Sb intake. Best for small blocks?
I had someone tell me that the M1 dual plane intake was about the best performer on a small block Chrysler. What's y'alls thoughts? They dont make this intake anymore from what I understand, and they are pretty pricey used.
Thanks guys!
This is accurate for a certain rpm bracket. Since the MP/M1/DP (DP = dual plane) is a copy of the early 340 intake manifold, it will perform like one. The amount of camshaft it will work best with is on the small side. Consider the cam size intended to be a true driver street cam with stock OE gear ratios and for the most part, stock converters though that is a little misleading, but IMO, a reasonable way to look at it. Changing a converter out for more stall cam be done regardless of the intake manifold being used to your benefit if the set up is right.
Also, do you guys know the significance of cutting down the divider in the middle?
YES! This was designed as a “Cheater” move when the rules dictated the use of a dual plane intake only. Removing the dividing wall, as said before, does indeed increase the top end performance of the intake as well as decrease the lower end performance. Originally outlined in the MP engines book for use on the Edelbrock LD-340 intake, the recommended cam usage was “Over .600 lift.”, which is a”Read between the lines” hint. Back in the day, if you had a cam with .600 lift or better, it was a big *** cam! While this mod works with smaller cams, the effect lessens somewhat.
Do not do this mod.
I have a mild build 318, 3.23 gears. But im moving to 3.55 gears. 302 heads with port work. .454/.475 cam. 1.5 roller lifters.
This is the perfect type of build for that intake manifold.
Other dual plane intakes will work well with build.
Edelbrock’s Performer or earlier DP intakes.
Weiand’s Action Plus or Stealth
Factory iron 4bbl.’s.
Someone mentioned the RPM. It will work, but I’m not sure how well with your cam since you left the duration out. At worst, it may (key word -> MAY) lack a small amount of low end for a very short rpm range. I’ve discovered this myself. If you can live with a minor lack of power compared to another intake, the. Go for it.
I thought the Holley Strip dominator was the best intake for a small block.
Total combo dependent.
The 302 heads I have were gasket matched and ported. I guess my question is, if the edelbrock air gap/M1 dual plane have runners sized to fit the 340/360 heads, what will it do with the 302 heads? Just not perform as well I guess?
Total depends on the gasket size the heads were ported to. What gasket was used to gasket match the heads?
If it doesn’t have an opening of the 340/360 head gasket, there is that small problem that everyone likes to make a mountain out of, a mismatch on the ports. The bigger the mismatch the worse the issue will be and since I have been there and done that a few times in the last 30+ years, at your current level of build, ignore it and worry not. If you can correct it, GREAT! If not, don’t sweat it.
What you NEED TO DO is measure the heads port window size and write it down and then measure (or have done for you) the size of the intakes port windows.
Do not be surprised if the intake can be opened up to the gasket size used for the 302 heads gasket matching. Especially aftermarket intake manifold.
