wells01

iTrader: (1)

Im Im looking to build a 408 on a budget,and was wondering how well the AI ported 241s would work?

garygnu

.consider some stock GM ls3 heads from SDPC for $650 a pair.

Blackpanther99

iTrader: (8)

Agreed^ LS3 heads will benefit you alot, if not L92s will do a good job also.

JakeFusion

iTrader: (7)

Agreed. The 241s have a pretty small CSA and port for the 408. That being said, they'd probably produce pretty insane torque.

badazz81z28

iTrader: (6)

It would probably drive just like my friends mustang...has some snap off the line, but coughs and dies right after. You think he is about to blow your doors off in the 1/4 and than fall on his face. I wouldn't put 241s on anything but a 346.

whatsa347

iTrader: (6)

I would think the ls3 with the smaller valves would make a nasty setup, I forget which sponsor sells them but I bet that thing would be a torque monster and make damn good power.

JakeFusion

iTrader: (7)

Yeah - stock LS3s aren't the best for a 4" bore - 2.16" valves are a bit much. The vendor you're thinking of is Ballistic Speed. They have put 2.08" valves in an LS3 head. Their Stage 2 looks awesome: https://ls1tech.com/forums/new-produ...1-engines.html

MAST has also done this. But it costs a whole lot more...

96capricemgr

iTrader: (1)

why are you putting the cart before the horse?

Is the 408 a repair?

power is in the topend more than the shortblock, don't let a fixation on displacement cause you to cut corners on the topend.

Now if you wanted to put the AI 243s on a 408 that would be a nice setup.

wells01

iTrader: (1)

The 408 is not a repair, just a thought right now. I just seen that some people have used the 241s on the 408 and i was just curious, but I do realize thats not the norm. I have a 01 z28 that I just resently bought, with cam only. A few weeks ago I guess it floated the valves and the intake on
#5 broke the head off, and got pushed back into the seat. The cylinder has some gouges or a crack not sure yet. I was gonna do a 383 if the block was ok, but now im not so sure, may go with the lq9.

96capricemgr

iTrader: (1)

100% of airflow has to go through the heads intake and exhaust and is controlled by the cam. What displacement does is allows you to use bigger heads or bigger cam or make the power at a lower rpm, but heads and cam are what really make power.

Point being if budget limited money is better spent on the topend. Ideally you can have both a larger displacement shortblock and a killer set of heads and valvetrain but most of us have limited budget.

If you want to do the 408 as a repair you could consider staying budget on the heads for now with the intent of redoing that later?????????????????

wells01

iTrader: (1)

yeah i see now what u meant by repair, so then yeah the 408 would be a repair from the ls1

01ssreda4

iTrader: (96)

I'd do it as a hold-over (until I could fund a better top end). It won't be a peak performer but nothing on a budget is.