Dyno Guesses & Bench Racing Forum - New setup 408 with 243's

Well I recently did h/c/I to my 01 m6 ss, the setup was prc ls6 2.5, eps 226/234 and fast 102. It put down 446/399 on a dynojet. Now I'm looking to step up to a larger cube motor using everything except the cam. I know the 243's won't be ideal for the 408 but this is what my budget allows. The cam will be a much larger eps cam. All done through the stock 10 bolt. Opinions welcomed
Tsp 408 or swanke 415
11 to 1
Tsp ls6 2.5 heads
Large eps cam
Fast 102/102
13/4 long tubes
3" duels with xpipe no restrictions
And all supporting mods execpt for rear end (I know it's next)
How much power is there to be gained. I know alot depends on the cam. This is not a daily driver so I want to go big( of course custom speced by Geoff ). I'd hope to clear more than 500rwhp and close to 490rwtrq. How does this setup sound. Thanks

Sounds pretty nasty to me. I'm thinking it gonna be a high 9s car if the 10 bolt don't brake..

Sounds pretty nasty to me. I'm thinking it gonna be a high 9s car if the 10 bolt don't brake..

you must be joking

What I'm I joking about. I know of a buddy with a 408ci N/A running high 9s..

What I'm I joking about. I know of a buddy with a 408ci N/A running high 9s..

Your right every run of the mill 408 with a 10 bolt is gonna run high 9's.. my mistake..

Lol@ high 9s.

Well this thread went south! I could careless about times at the moment. I was just curious about the 243s on a 408. Would I see a significant gain for the money? Yes I've seached and seems to be from 430 to 530.

I used the swanke 415. The short block was my only change. My stock short block made 480/435. With the same top end and my TEA 243's I made 515/500. So not a bunch of hp but a lot of tq.

Thanks jimz that's just what I was wanting to see. What size cam is that. Also are you satisfied with the swanke block?

I was going to say, you will see a nice bump in torque, but may not completely "satisfy" what you want for horsepower. However, if you're doing a new cam, that will completely change a lot...what cam are you thinking about running?

I'm gonna get a custom cam.(eps) Id like to go pretty large. I'm not familiar with durations for a 408. What would considered large. For instance
346-trex,polluter,texasgiant=large.
408-xxx=?

The cam is a comp 236/242-601/610 on a 113 lsa. Thinking about a custom cam but do not want to sacrifice tq. I think the short block was a great bang for the buck value.

Im using TEA 243s on my 408. I just made 512hp and 480ish tq I think it was last Weds through a 4L80 and 12 bolt. Sure some better heads would only net better results.

Im wanting to use a spdc l92 416 with the ported 243 head. I know I'm pushing it, but I don't want to regret less cubes later on. I seached and found that it would work just could not find any #. How ridiculous is this? Also bought 1 7/8 headers. Still waiting on cam specs. What cubic inch would you go with:
Ls2 402
Lq9 408
Ls3 416
Thanks

The build has changed a bit.
Ls3 416
11.5.1
Tsp ls6 2.5 62cc
Eps 243 251 .627 .632 113+2
Fast 102,102
Tsp 1 7/8 LTs
3" duels
I'm hoping to break 500rwhp 480rwtrq. Heads are just temporary. AFR 245s will come next. Do you think I'll hit my goal?

The build has changed a bit.
Ls3 416
11.5.1
Tsp ls6 2.5 62cc
Eps 243 251 .627 .632 113+2
Fast 102,102
Tsp 1 7/8 LTs
3" duels
I'm hoping to break 500rwhp 480rwtrq. Heads are just temporary. AFR 245s will come next. Do you think I'll hit my goal?

You will hit 500 to the rear with that setup no problem.

Gonna go ahead and get tea trickflow 245s and sell the prc's. So much for a budget! Whats needed to use stock rockers? Shims? What size( not lenght) pushrod? Going for a goal of 550hp 500trq