MP Pre-magnum 360 Short block & Edelbrock Heads "A" Body

[rraulston]

This is a repost. The subject on the last one was misleading and i couldnt change it. So here goes. I have a 74 Dart Sport. I purchased a pre-mag 360 short block, the 10 to 1 model. Then i bought a set of edelbrock heads. I spent over an hour de-burring them. The rocker shaft pylons would even let the shaft sit in the seat. And you have to have the original shaft bolts because you will need the spacers when using Comp Cams roller rockers. So i got the heads all torqued on and went for the intake. I pulled threads on three holes. Right out of the head. They dont tell you you might need longer bolts. These holes are cut all the way through the head into the area where the oil falls back into the pan. So i used longer bolts and finally reached torque. I work at Lear Jet so i do aluminum all day. Any ways, i thought it was down hill from there. NOT!!! I wanted to pre-fit my Hooker Comp headers, well they wouldnt sit flush on the mounting surface. The center pipes hit a cast part of the new block and make about .080 gap on the bottom of the flange. O.K. so i hate headers anyway, wire wheel off the rust on the factory exhaust manifolds, try to mate them to the heads and guess what, NOO!!!! They dont sit flush either!! They hit the bottom of the head!!! Ime screwed!! I could have the factory manifolds machined at an angle, but i wanted the xtra header power. Can anyone offer me a way out ??!! Ray

[djswwg]

I'd be real tempted to call Edelbrock and ask them what's up. There stuff is usually better than this. Although I prefer competitors intakes to there's in recent years.

[Quartermileflash]

I purchased the same block you have and had the same problem with my Hooker Comp headers.
What I had to do is grind down the cast part of the block where the headers hit. Easier to pull the motor back out of car to do this. Wasn't my idea of fun,but you do what you gotta do. You'll get more power from the headers anyway. Hopes this helps.
Quartermileflash
1973 360 Duster
Best 1/4 mile:11.32 @ 119 MPH
1996 Dodge Intrepid
1984 Dodge Ram P/U

[Dart]

I had the same problem with my LA360 block in my '70 Dart. I am running Headman Headers. I dimpled the header tubes on the driver side to get them to clear the block. If you have the motor installed, pulling the header is a lot easier then the motor. I just heated the tubes with a torch and whanged on them with a ball peen hammer until they were flattend about 3/8".

PRO has the same engine combo you have (LA360 10 to 1 and Edelbrock heads) in a '64 Valiant. He has 3.23's and has run 12.9 quaters with the combo at ~5500ft elevation.

I don't think you want to run the manifolds with that combo. They will basically put a cork in the flow of the heads. You need to run headers in my estimation.