360 LA Installing 340 X Heads-Hi Pro Mods

[OutLawBiker]

Hey Everybody,
In my 1973 Road Runner I am installing 340 X Heads on my 360 LA engine and would love any advice on installation and high performance tricks...

73 Road Runner 360ci LA version
570 CFM dual feed single pump Holley carb.
Edelbrock Performer intake manifold
MSD Ignition and MSD Super Blaster 2 coil
ERSON CAM .472 lift 296 duration
Custom Wrap Headers

Thank you kindly for any extra steps taken on my behalf-
Looking forward to your replies-

 

[Russ69Runner]

I know you can swap different head's to get better flow in and out. I think I would call Summit racing they have a tech line. These guy's are good. I have had head's ported and polished to make better flow. But better to talk to an expert on this one. I have surfed the net and found out things to help me also. Good luck maybe some one here knows the answer. Russ.

 

[Rich B]

Back in those days the quickest idea was to rapid advance timing. Dual point distributor would actually provide a hotter spark due to the overlap of the 2 point sets; mechanical advance rules over vac and weights......

Cant imagine the change to pointless ignition has any advantage other than no-skip of points (floating/chatter) with high rpm’s. Not aware of any engines then that ran well without shift beyond 6K rpm. They were all peaked out.

 

[Rich B]

Oh too, you can put in the ultra-thin copper head gaskets which would emulate the same thing as milling the heads to increase compression ratios. Um, by ‘73 not a bad idea. Today’s fuels will support the higher ratios pretty well it seems. https://www.jegs.com/p/Mr-Gasket/Mr-Gasket-Steel-Shim-Cylinder-Head-Gaskets/746654/10002/-1 Similar idea.

 

[OutLawBiker]

Thanx for the direction to Summit Racing Russ - The guy I talked to wasn't old school. I'll check back tomorrow.
Rich the dual points' distributor concept is great I'm looking into that-also the ultra-thin cooper head gasket as well.
Thank you both for your help
Important note:Following the 340X install and the first re torque to 95' lbs I slowly developed a worsening backfire through the exhaust and did I ever panic. I mean to say, I flipped the hell out! If this ever happens to anyone else, yeah don't do that.
I finally discovered it was backfiring only on the left bank and went straight to the solution-I needed to re-torque the left head a second time!
I hope this helps someone else suffering from long timeouts...lol

 

[Russ69Runner]

Working on motor's is a learning curve. It is hard to find the old mechanic's out their that worked on motor's like back in the day. Every thing now is typed on a computer and not hand's on. Lot of those old guy's a have passed on. If you can find some of the guy's that race in your area or hot rod guy's maybe an advantage. Guess I am lucky grew up working on motor's and know a few older guy's that have Mopar's. Also have some good shop's that have been around for a long time that have machine shop's. Wish you the best of luck with the car hope you get all the kink's worked out. Russ.

 

[ACME A12]

Reader's Digest version: Your initial thought to go the MSD route is good. Stay the course. No need to revert back to even older technology (dual points) unless you are restoring a bone-stock Hemi or A12 RR. Need proof? Go to the track and peek under every open hood. Count the number MSD set-ups versus the number of guys checking the gap on their points. Case closed.

 

[Rich B]

Haven’t seen mentioned either the https://en.wikipedia.org/wiki/Fan_clutch Still belt driven but only engage when engine is hot. Now.... these junk electric fans, might as well have windup fans.

 

[Russ69Runner]

Never liked the clutch fan's they could fail with out notice. So threw them in the trash and bolted the fan straight to the water pump.

 

[ACME A12]

So threw them in the trash and bolted the fan straight to the water pump.

Which is why today when you go to restore an A12 or a Hemi car a correct 070 fan clutch is worth its weight in gold...