LE2 port job?

[Z4Performance]

I have a chance at a set of LT4 heads and Intake for 400.00. My question is I was already saving for my LT1 heads and intake to be done by lloyd or would it be better to have him do the LT4 heads and intake?

[96z28SideSwype]

He's on this forum so I'm sure he'll respond here sooner or later @NightTrain66


Silver 96 Z28 Silverback-DD
Green 96 Z28 Greenbean-Drag car

[NightTrain66]

depends on the budget and cubic inch of the build and if boosted or not.

If this is a N/A 350/355 spinning 6500-6800 RPM, stick with ported LT1 castings with 2.00/1.56 valves. The measurements in a few ares end up right for this set up.

If fully porting the LT4 castings and going back with 2.00/1.55 or 2.02/1.60 valves, you can't really make the bowl shaped like you would like and the pushrod pinch is still a lil big for the bowl/throat and the air at PR pinch is not moving fast enough in relation to the .

The LT4 head will "work" alot better by installing larger valve seats and 2.08/1.60 valves to get the throat and bowl area large enough to suck on the pushrod pinch of the LT4 head good enough for the head to "work".

At this point you end up with a 215-220 cc intake port, 2.3"+ at the pushrod pinch that will flow 300/220 CFM and "the head" will work well (air moving correct speed in the right areas in relation to other areas).

This will be OK for a 6500-6800 RPM 383 but not a real good shoice for a 350/355 unless you have light car and/or lots of gear/stall only worried about power 5500-7000 RPM. It would not be a real fun street car (feel kinda week 2000-4000 RPM) on a 6200 RPM 350 using a CC 503 cam.

You are also about to wrap up alot of $$$ in some factory LT4 heads (portwork, valve seats, machine work, valves, springs, etc) and I believe ana fter market set of Trick Flow heads with bronze guides, thicker decks, thicker/better aluminum, etc would be abetter starting point and just sell the LT4 heads to some Corvette guy that doesn't know any better.

If it is a 10 psi or more boosted set up, the ported LT4 heads has a larger cross section at PR pinch and will help make a lil more power when running 10+ psi of boost. When being "blown thru" with blower/turbo instead of "sucked on" like a N/A set up, the head will act differently and the port being a lil too big at PR pinch is no big deal but N/A is a lil less forgiving a better working head (ported LT1 castings) will be a better way to go.

Lloyd

[blkchevyz]

sort of on topic, Lloyd whats your preference on after market heads?

say someones trying to get the most out of a n/a 383 or more ci.

[SexyTransAm]

just sell the LT4 heads to some Corvette guy that doesn't know any better.

lmfao love this part!

[NightTrain66]

Blkchevyz-

If using standard port location (no raised runners, using LT1 intake, no offset rockers, etc) I like the ported Trick Flow heads with 2.05 (21 degree) or 2.08 (23 degree) /1.60 valves, chambers anywhere from 62 to 52 cc, lots of cross section over shortside and at PR pinch but still using standard rockers (not-offest), bronze guides, thick aluminum everywhere, thick deck, good quality aluminum, etc.

Kyle-

I post threads every now and then looking for cyl head cores and most people send me PM's saying "I got these 374's for $150", "I got these 643's for $175", "I have a set of 561's for $160 shipped", etc.

and then I sometimes get a PM saying "

"I have these aluminum LT1 heads from my 94 Corvette Gran Sport special edition limited series and they are casting # 10128374. They are #'s matching castings for the 94 Corvette Gran Sport special edition limited series. I will take $450 for them plus shipping".

If they believe 374 castings are worth $450 I can only imagione what they would pay for the ALL MIGHTY LT4 heads.

Lloyd

[Z4Performance]

NightTrain66 thanks for the info I knew you would respond. I think I will save my money and just have you work my stock heads and intake soon. I do have another question for you. Would you do the coil conversion or stay with the opti. I am going to doing a 383 with your LE2 heads and intake with the cam you recommended. Or should I just LS swap it lol. Just kidding.

[NightTrain66]

not sure of the exact build or budget but if it is a 10.5-11.0 to 1 N/A 383 using a mid 220 duration cam and spinning 6000-6200 RPM on a budget build, opti is fine, especially if you already have the opti, coil, good capa nd rotor, good plug wires, etc.

If it is a more serious set up (more compression, bigget cam, more RPM or boosted) or if you are gonna have to buy a new opti, new coil, new cap and rotor, plug wires, etc, anyway, I believe that $$$ should be put towards the 24X set up.

Lloyd

[HellTeeOne]

I post threads every now and then looking for cyl head cores and most people send me PM's saying "I got these 374's for $150", "I got these 643's for $175", "I have a set of 561's for $160 shipped", etc.

and then I sometimes get a PM saying "

"I have these aluminum LT1 heads from my 94 Corvette Gran Sport special edition limited series and they are casting # 10128374. They are #'s matching castings for the 94 Corvette Gran Sport special edition limited series. I will take $450 for them plus shipping".

If they believe 374 castings are worth $450 I can only imagione what they would pay for the ALL MIGHTY LT4 heads.

Lloyd

LOL! I see gems like that all the time when searching parts for LT cars on craigslist.
As for the OP, I'd see little reason to spend the extra $ on the LT4 heads unless there's something highly specific about your build that would call for that casting for some reason. The money in cylinder heads isn't in the casting, it's in the components and quality machine work applied.

[Soxxpuppet]

Not to mention he'd need a lt4 intake manifold. Bone stock heads will make good enough power until your ready to get serious. Not to get to off topic. But this is a good reason to love Lloyd. Hes a man that speaks the truth!