magnum intake, LA heads. can i?

-
D

dusterbd13

Well-Known Member
Joined
Mar 16, 2008
Messages
650
Reaction score
60
Location
albemarle, nc
ok, so im looking at all my options for going EFI on my 360 LA duster.
one option i hadnt given much thought, but seems like a really good idea now that im doped up on cold medicine, is to use an injected M1 intake from a magnum motor. only problem is my LA heads. could i re-drill the bolt pattern, and plug the magnum pattern like the professional products intakes ive seen and used?
dont see why i couldnt use a LA style gasket glued to the head as a drilling jig, centerpunch the hole accurately, and drill it with the press.

or am i asking for trouble and leaks doing this?
reason im looking at this option is that i dont think i can drill my victor jr intake for injectors without welding bungs. just dont think theres enough thickness in there.

other random question: how much could a stock magnum v-8 throttle body and rails support?

Michael
 
I think you mean use the magnum intake gasket glued to the head to use as a template. Even with that you'd have problems because the magnum intake bolts go straight down, not at an angle like LA heads. I think the only way you could even get close is if you had an engine block the same deck height as yours and heads bolted to it then set a set of magnum gaskets on it then the magnum intake and clamp it down so it can't move around and drill down through the intake holes. The problem when would be accuracy. I have had a lot of experience drilling and I wouldn't even attempt it. I'm sure a competent machine shop could do it though.

No true idea what the stock stuff supports. Probably not much more than 350 would be my guess because that beer barrel intake goes pretty flat after 4500.
 
The stock throttle body and rails can support alot of HP. Upgrade the injectors and have the TB ported and they are good to go. Why buy expensive billet rails when the factory stuff is fine. A factory TB is somewhere around 600cfm and you can have them opened up to 55mm+, they will work quite well. There are alot of people that will say you can get more HP from a carb but I am using my factory EFI stuff cause I like the reliability and once it is set you can forget about it and just have fun driving it.
 
I did this with a stock intake clamped on the LA. Figured out the drill sizes, pilot inside a DOM tube 1 1/2" long, pulled that out then used a copper tube to guide the drill for tap size. It dosn't leave much meat to grab a bolt so we made some studs. Did this for my son to stick an LA we had under his F.I. in his truck not for any performance reasons.
 
if your just looking for the EFI reliablity and are going to keep the engine stock may I suggest dodge TBI, its a bolt on only thing you have to figure out is the wiring and thats not hard at all
 
Coronet 500 said:
I did this with a stock intake clamped on the LA. Figured out the drill sizes, pilot inside a DOM tube 1 1/2" long, pulled that out then used a copper tube to guide the drill for tap size. It dosn't leave much meat to grab a bolt so we made some studs. Did this for my son to stick an LA we had under his F.I. in his truck not for any performance reasons.
Click to expand...

im having a hard time picturing this. how di you locate the holes into the heads, and the correct angle? did you use the tubing as a guide to locae the angle of the holes correctly?
in other words, can you elaborate some more on your setup and process? im assuming this was the stock "beer barrell" magnum intake youre referring to.

And i cant go with ANY stokck TBI. reason being that im putting 425 to the rear wheels off the bottle. add in the 150 shot, and....
also, port efi will allow me to ditch the nitrous, and go blower.
im looking right now at an early magnum M1 4 bbl intake with the adapter for the stock TB. if we can come to an agreement on a price, i think i found my manifold. just a matter of figuring out how to modify it.

michael
 
If you plan to use stock Magnum EFI on a stock stroke engine, I would stay away from the M1 except for a real light vehicle in all out race application. They murder the bottom end and mid-range HP and torque. I have talked to several guys who have taken M1 intakes off their trucks because they hurt performance. (The M1 might do better on a stroker) Stock beer barrel runs out of steam a little over 3500 rpm, but responds well to mods. A modified stock intake or the Hughes air-gap would be best for street, and for trucks.

Watch how far you go with TB mods, another bottom end killer on nearly stock engines.

If you want a car engine with EFI (emissions exempt vehicle)you may consider an air-gap or RPM with Fast EZ EFI.
 
Yes a beer barrel clamped onto bare LA heads bolted on a bare block, slight grinding on the back of the manifold, as it hit the LA block, then it can slide back to line up with the head. The steel tube is OD same as the Magnum intake bolt hole ID for a snug fit. Steel tube ID same as first small pilot drill bit, hand held electric drill, slow, patience and lots of spray lube. Then remove steel tube, insert copper tube which is same OD as the steel tube, but has a larger ID same as the tap size drill bit. Starting the tap is the tricky part, running it through the copper tube while in a vice can make a guided tap to start then have another tap (same size) to finish all the way through. Clean up the heads real good and assemble then install on the LA shortblock. Don't try it on the engine to be used as you'll fill it with shavings, real messy process, but we did it. I have seen some guys who have made proper jigs to fit on the head and set up in a drill press.
That's about it, hope this answers your question.
 
ok. i was thinking you were talking about drilling and tapping the heads. im talking about redrilling the manifold to fit the existing la pattern in my indy heads.


and im npt going tbi style injection if i can help it, ive already got a lot of port injection parts collected. and i just like the style of ecm better than the tbi stuff. and its a lot more suitable to my end goals.

michael
 
You must log in or register to reply here.
-

Back
Top