car is a impala SS(lil heavier then a f-body!)
built to the ***** tranny with 3600 TC and 3.73's in the rear

Motor Eagle forged 383, motor is being rebuilt with new pistons cause I need to go .40 over so I need to choose pistons also.

I have stock GM LT4 heads and intake. What do I do slap the LT4s on the new stroker as is, send them to AI to get worked? Sell them and go with fully ported GM LT1's or aftermarket such as AFR's???

I would like to see about 475-525RWHP and don't wanna have to turn crazy RPM to do it.

what would you do......

 

Send them to lloyd or AI

 

Right off the bat your goal is unreasonable.
475-525rwhp without turning some rpm is just unreasonable to ask of an NA setup.

My vote though would be talk to Advanced Induction about either ported LT1s or Trickflows.

Should be really easy to find a benchracer who wants those LT4s.

 

by not turning a bunch of RPM I mean I would Like to see 6500-6800 max shift points

 

The pcm only allows for 7000-7200 depending on the pcm and if you get lucky and find one that revs a little higher than most.
This is going to be about the top performing hydraulic setup with "normal" parts you are going to find.
http://ls1tech.com/forums/lt1-lt4-mo...o-results.html
This is an M6 car so even the exact engine in your car will put down less.

Most of us with b-bodies that perform "better than they should" run Advanced Induction stuff, their ported LT1 castings at that not aftermarket..

 

Shifting at 6500-6800 means your peak power will be around 6100-6400. VERY unrealistic for your goal. My 383 makes 455whp and I've got to push the PCM to its very limit - 7100 RPM - to get those numbers.

 

worry about avg power more, don't get caught up in peak rwhp numbers. so many factors change the outcome but the timeslip and drive ability of the combo tell the true tale. case and point. my 79 Z28 with a 468 cid bbc only put down 480rwhp but on the engine dyno it made 630hp. the car runs 10.40's at 130mph n/a id say thats a pretty solid 480rwhp for a 3650lb car. tranny, gear, converter etc. skew the power numbers. race the cars not the dynos.

 

The TH400 drags down rwhp numbers a LOT compared to a 4L60E.

 

As stated above,use the dyno as a tuning tool...The true test is running it at the track..Last yr I ran 11.05@122mph,my car put down 353rwhp and 321tq..There are alot of things that go into getting the power to the ground..

 

Stock lt4 heads can be hogged out to flow just as well as the Afr 195 heads. However you will need more than that to push that heavy beast into the 10s. Dart pro 1 or afr 220s should do the trick. Then you can sell me your lt4 heads cheap cuz i don't wanna go that fast. Lol

 

I thought the op was looking to race a car rather than a bench. If racing a bench then heck yeah he should do the AFRs or keep the LT4s.

If the few NA 10 second b-bodies one uses trickflows and the others use Advanced Induction ported GM castings, the 200cc version and one of those cars is a stock shortblock. The car with the Trickflows is the lightest but NOT the fastest. There are some max effort solid roller strokers with AFRs and LT4s, they are up in the 11s.

For max effort with a big budget I would do the AI Trickflows as based on RESULTS they work better than the stuff the benchracers push. For most builds though the AI ported 200cc head is really a wonderful choice.

 

Here goes Caprice with the LT1 stock heads are the best BS again .

No bench racing, a large percentage of the fastest LT1s *PERIOD* are using AFR heads.

...but they don't count, since apparantly they are "race cars", and will blow up if they have to stop at a red light.

OP, your rwhp goals are unrealistic but if you have your LT4 heads ported by a reputable shop and get a cam spec'd to match, your 383 will fly. LT4 heads have tons of potential, and are superior to the LT1 heads both as-cast and when ported. It makes NO SENSE to sell LT4 heads that you have already to run an LT1 head setup, that is rediculous.

Not just AI or LE can get the job done right, many other companies like GTP, LPE, or TEA, can all do a killer port job on your LT4s.

 

A critical piece of decision making is look at effort for a result. When you can compare two cars and one spends 30% more for the same or even slightly better result it should raise questions about how if spending more on "better" parts really works.

Far as fastest NA f-bodies the ported stock stuff and ported trickflows makes a VERY good showing, not necessarily the fastest but when the pump gas compression and moderately heavy weight are concerned a person who is open minded rather than blind benchracer will take notice.

 

Are you trying to be dishonest putting words in my mouth in an effort to discredit me or do you just have a hard time reading?

 

This thread is about to get closed, and if it does get closed, there will be infractions issued to the trouble makers.