454 mag looking for a little more hp
 

Recently picked up 242ls carbed 454 mag with 600hours.. Needs new valve guides so was thinking of pulling the heads and sending them out for a port and polish. I have a set of EMI thunder manifolds that I'm putting on on the spring. Anyone know if there's any power to be had out of these heads or should I be doing a cam also? Anyone with experience with this I would appreciate it. I don't want to build a high HP motor just looking for another 50-75 ponies.

How many Ben Franklins are you willing to spend, 10-20-30???

Don't want to spend a lot. Like I said not looking for much power. People tell me these motors stock are breathing through a straw. I figured I'd let it breathe better with exhaust and a head job.

a nice intake, the exhaust, hp500 carb and a better ign system will wake it up

any recommendation on intake and ignition? anyone had heads worked? maybe different rockers etc

Single plane dart. Or the cp performance single plane. Msd distributor with box and coil. After that and the exhaust next would be cam and valve train.

Am I looking in wrong place or are dart heads really that much money. If so this are crazy priced

Does anyone have any experience porting and polishing the stock heads? Was it worth it ?

If you want another 50-75 HP. This is what you need to spend your money on.

A new cam, I'm going to sound like a broken record but call Bob Madara for that, if you need his number I will give it to you. A V-6 module for your ignition, don't waste your money on MSD stuff, you won't see any gain and it's less durable. Find an HP500 carb, or a Holley 800, then the valve train to match the cam. Then look for a nice performance exhaust manifold, this is a must for a performance cam. If you have some spare coin, having the exhaust ports ported would help but I wouldn't do more than that. For $2100 you can get a set of AFR ovals, when combined with the right cam would yield you at least a 100 hp increase. Head work is expensive and it doesn't take much before it's cheaper to just buy new heads.

You don't need to replace your intake- the stock Mag intake is very good until you're spinning over 5500 rpms. Good luck with your build.

Merc ign junk in my opinion

on a major budget? used hp500 cam intake carb pluse the exhaust you were going to get...should take you around 420. just spend a day or two searching here, there are more "I want to build my 454" threads than you can count.

no budget just want to keep near stock reliability

Your not listening to your mentor,:lolhit: well then listen to these guys. You've already got a good, heavy duty lower end, now give it a cam,exhaust,and clean up the heads!! No reliability will be lost.Might even gain mileage and torque with the right cam.Did you call Bob M? There is no lack of experience on this forum, listen to them. Build it right once, with good know parts and then hammer down.! See ya in the spring! Gotta go do my motor now! Dam it!

so i just got the heads back and picked up my cam and timing chain. As far as the EMI thunder exhaust with short risers am i going to have any problem with reversion? The cam is 228/236 duration .537/.555 lift 114 LS

Here we go, :argue: with the LS being at 114* you won't have any problems with reversion. Well, until you load up the ass end of that tub with fat chicks, then it'll be an issue. Nice cam btw, let's get it together.

Who ended up doing you heads for you? And why not the long risers?

A local machine shop that does a lot of marine and automotive motors. Im getting the exhaust from a friend and that's what he had.

Cool, where u ever able to get ahold of bill? I know what you mean have to use what u can get...

Ya I did talk to him thanks again. He said he was getting ready to retire and gave me a little heads up on what I should have done.

Ok cool. Glad the build is going well. Are you going to dyno them when your done

no I don't think so. too much work to get it somewhere etc.