[LaserRed97GT]

Hi there guys. Just started posting on this site yesterday, but I have been reading for a few weeks as I tried to decide which parts to buy for some recent mods. Now I have a dillemma as to whether I should keep going or to put her back together with what I have.

What started this latest mod session was finding a nice score on some PI heads on craigslist with intake, plus aftermarket fuel rails, ported (poorly) upper plenum, timing adjuster, and I ended up getting the whole shortblock too.

So I decided to add some cams at the same time. I ordered up and received the Comp 270's and beehive springs (which I will degree), and some FRPP U/D pullies. I also got the FRPP head install kit. Now I'm to the point that I "could" put the engine back together with what I have, or I could go a little further and do a few more mods before buttoning her back up.

So here is what I am thinking. I can get a 3 angle valve job done from a machine shop that does a lot of work for my company for $150. I could get a 5 angle for $235. I could port the heads myself (done a few sb heads before) using the Sean Heyland book as a guide before the head job. Then I was planning on adding LT headers (BBK) and matching (BBK) o/r X-Pipe.

My main question is: If I add the 3 angle valve job (or 5) and the headers, will I see a SIGNIFICANT improvement over just the manifolds and non ported/3 angled heads? I have seem anywhere from 5-15% before from the valve jobs on small blocks, and anywhere from nothing to 45HP from headers, but I have little experience with modulars.

If this were your build would you spring for the extra $900 or so to gain th XX amount of HP, or is it not worth it?

I do plan to have either combination tuned (probably by me with a Tweecer) and in the future I do plan on adding turbos or a KB blower. When I finish my bottom end build (maybe a year or two off).

What kinda HP #'s difference are we talkin between the two combos?

Thanks for help from the "hive mind".

[G.T. Rags]

unfortunetly these motors don't really make big numbers without forced induction. the rwhp difference between the 2 setups is going to be negligible..... 10-15 at best

[4.6LMadness]

281ci is kind of pathetic when you think about it. The displacement isn't there to make big numbers NA. It could be done but to much time and money for most people.

[LaserRed97GT]

Originally Posted by 4.6LMadness 281ci is kind of pathetic when you think about it. The displacement isn't there to make big numbers NA. It could be done but to much time and money for most people.

Yup. I agree. Some people have done some amazing things with these engines though. I think I will take the shortblock I got for free, and tear it down and build it into a nice forged bottom end. Then I can really crank up the wick.... Time for some chassis mods too methinks....

[Willy Mo]

you wont see to much more HP until you go FI to take advantage the porting and valve job. but gains willbe there. 10-15hp would ba a safe guess i think. butcould be more or less.

[LaserRed97GT]

So, I went and did it. I was back and forth about what to do, and decided to jump in with both feet. I am going to have the three angle valve job done, and have already begun the porting/polishing. Then I went and found an awesome deal on a set of almost new <2000mi 17x8 and 17x10.5 CHROME Bullitt's. I then ordered through work, a set of BBK ceramic headers and x-pipe, a set of FRPP header locking bolts, Steeda u/d pulleys (my supplier says that FRPP is no longer making these for this car), a BBK 78mm throttle valve/plenum, and a set of FRPP 4.10 gears and install kit. I also ordered a set of Eibach springs off ebay for a good price. And I got a great deal on a BBK CAI.

All of this is now going to go on in the next few weeks as I put her back together, and from reading this site, I have forgone my plan of building the 4.6 shortblock, and will instead find a 5.4 and build it.

What do you think this combo will pull? I still need to get a tuner.... I was thinking Tweecer, but should I get a handheld, or go the custom tune route instead?

[4.6LMadness]

4.10 in a 5.4L?!?!? say hello to traction problems

[LaserRed97GT]

Originally Posted by 4.6LMadness 4.10 in a 5.4L?!?!? say hello to traction problems

I would imagine that would be an issue,

I would probably knock it back to 3.73's at thaqt point.

[mpboy]

i have heard that the mod motor heads can be tricky to port if you haven't had much experience. i even read somewhere that unless you have a CNC machine to not even try it. there are guys on here that have done it though. i think sweet is one of them. not saying you cant do it, but iv heard horror story's from guys that have been porting heads on older motors for years

[LaserRed97GT]

Originally Posted by mpboy i have heard that the mod motor heads can be tricky to port if you haven't had much experience. i even read somewhere that unless you have a CNC machine to not even try it. there are guys on here that have done it though. i think sweet is one of them. not saying you cant do it, but iv heard horror story's from guys that have been porting heads on older motors for years

Well, it's too late now. I've gone and done it. Really all I've done is follow the guide in Sean Heylands book about the 4.6 Mod Performance. I cleaned up the valve bowl area, smoothed the short side radii, and port matched them. I left the middle of the ports alone, as well as the area where the injectors spray. I will only be polishing the exhaust side.

Hope I don't screw them up too bad.

[zigbigadoru]

yea.....you dont want 4.10s if your going with 5.4 even 3.73 is going to be a challenge from what i udnerstand. if you keep those 4.10s stay 4.6 and just get pi heads/intake and you will be happy.