360 port and polish help

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Gus Loza

Gus Loza

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im building a 408 stroker right now i have a set of 360 la heads with 2.02, 1.60 stainless valves. my buddy said i should port and polish the heads to benifit the motor, so when i went to this guy buy my house who does good work and he said he charges $500. i thought that was too much so i didn't do it. i was wondering how hard it would be to do it myself. there was a website that had a video for sale on how to port and polish and thought i should go that route. what should i do? this is frustrating, especially when you have thousands of dollars of new car parts just sitting in boxes for the past couple of months
 
I feel $500 for P&P isn,t such a bad deal for your heads,do you really need it though?A 408 will be a very stout motor for around the street.Unless your plans are for the strip?You,ve already spent thousands,whats another $500 for your heads to breath better?
 
pettybludart said:
I feel $500 for P&P isn,t such a bad deal for your heads,do you really need it though?A 408 will be a very stout motor for around the street.Unless your plans are for the strip?You,ve already spent thousands,whats another $500 for your heads to breath better?
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A simple clean-up you can do! And will increase performance, but to actually port them, you could end up with less performance, if you port in the wrong places.

My first set of heads i ported, made my car slower by one full Second!!! at the drag strip:angry7:.........................
 
i ported a set of Js way back when, they didn't do anything, not too long ago i ported my 906s on my 451 stroker, car picked up a good .1 & 2 mph, this doesn't sound like much, BUT i was already in the 10s @ 120+ before the porting. You will need a decent set of heads to benifit that 408, those Js will hold it back, even with the 2.02s, but thats not to say they won't work, i wouldn't mess with them, or drop anymore $$ in them, either run them "as is" for now, then save for a nice aluminum set, or even some RHSs, stock they flow 241 with the 1.92 valves. i paid 875.00 for mine ready to bolt-on from Hughes.
 
If you've never doen it, I wouldnt bother. Have a 5 anle valve job done and run them that way. It's a small port for a 4" stroke engine. But it will work that way.
 
You truly need someone to show you where to cut and where not to.Or start with heads you dont care about for practice. But the only way you will know whether it is working or not is if you have a flow bench. More air equals more power.

The simplest thing you could do is a port match to gasket size and blending the bowls in after the valve job.
 
Speaking from experience on this subject either cough up the $500 or just cleanup what ya have. Two things to think about is -does this guy have a flow bench and know what he is doing? I have seen several "PRO " p&p jobs that killed performance. Also if you don't already have the neccessary tools like a good die grinder- dremel tool and the good carbide cutters and sanding and polishing bits you are going to spend 1/2 that amount in tools not to mention the 20 hours or more for a novice to do the job.On my "J" heads I ended up with some port matching deep into the port and some cleanup around the guide area and unshrouding the valve/seat area and called it good. That still took me agood 10-12 hours to do. Mopar sells a template kit to port with you could try that also
 
thanks you guys for the advice. i will probably just get them port matched withe gasket and intake for now and save up for the aluminum set later down the road.
 
you need to really know what you are doing and have the idea fully grasped before porting'em yourself.

However you can get good numbers from j heads if you know what you are doing, which many don't.
I have less than a grand into my J heads + my port work and have over [email protected]

A good 5 angle VJ and mild bowl blend will net you around 240cfm w/2.02
every 5 cfm is worth 10 hp.
 
have your machinist do a bowl plunge cut and smooth them up around the valve but leave the floor and roof alone unless you know how or have porting templates
 
I was quoted $1300 to have mine done. This was also to have flow tested. $500 is great. I took them to a friend and he worked them over for me.
 
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