mag pushrod tunnnel clearance ?

not sure on the clearance, but I`m curious what combo of parts you are using. I just put together an LA/mag. combo and didn't have any problems. I used an 85 roller block, mag. heads, edelbrock hardened pushrods, comp cams studs/guide plates and 1.6 chevy roller tip rockers. is it a hyd. flat tappet cam/block?

It's an early non roller LA block & the heads were some bare new ones I bought a decade ago & I need to find the receipt for them (might be EQ's which are very good). I Used OE MP mag rocker arms/studs/guide plates & adj MP pushrods. EDIT flat tappet cam

I used Chevy 1.6 roller rockers on my mag heads and I had to do a bit of grinding on the parting lines and a bit more....... Easy work with a die grinder....... TBF

I should also mention I was using a non-roller block so the pushrod length was longer and I think this made the problem worse...... Roller lifters and shorter pushrods would help........ TBF

Yes I was real fortunate to have had those MP adj LA pushrods on hand which were much longer

Anytime you change the rocker arm ratio from a 1.5 to a 1.6 you move the pushrod closer to the center of the rocker arm

Which if mags were 1.5 I'd be in even worse shape. Cab I think I'll keep grinding till I get the .060" you recommended. The walls are thick so no problem there it's just that I dont like porting so the quicker I get enough clearance the better. Thanks guys!

I was under the impression that the adj pushrods were for findling the proper length and then having the real deal made.. The few that I have seen dont look strong enought to use in a running engine..

These are MP ones meant to be run. I'm assuming that a "checking" pushrod has more adjustment so you can find the correct length needed on any engine but I'm not sure as I ain't never had one in my possession & that extra length may make it unstable but I do not know that to be a fact. I tried to post a pic of the the MP ones I have but my camera setting was too high & this site wont accept it. In my case iirc even the MP fixed length ones for the conversion were too short

i used the MP adjustable pushrods in a 3.9v6 i put together a while back. i put a lot of miles on it before i sold it. it had stiffer than stock springs on it too. you should be ok with them

.010" is plenty and it's unlikely you need to grind anything.

The parting line was substantial & was touching the pushrod so it had to go. With it gone & everything smoothed a bit I do have more than .010" right now