Ok so I have a pretty stout 383 (specs below) and am looking for a complete exhaust setup. I was thinking about the 1 5/8" hedman LTs with custom y-pipe into a 4" hawks sinister system.

My concern is if the 1 5/8" primaries are large enough to support the current mods?

388 fully forged w/ H-beam rods
XE 284 Duration at .05 240/246
port polish 2.02 1.60 double humps
port matched weiand stealth 2" intake ports
1" aluminum spacer
1.5 roller rockers

I think that covers engine mods.

I was hoping to get around 500+hp out of this at the motor.

 

I would sell the double humps to a resto guy and go with a more up-to-date aftermarket aluminum cylinder head. Technology has come so far in that arena, there is no reason to saddle yourself with a head that was developed in the 1950s.

Also, I'd say 1 5/8s are too small if your goal is 500hp.

 

I want close to 500/500. What head would you recommend? I looked into AFR awhile ago but it seems like you pay for the name.

 

Long tubes are a pain in the butt with a 700-r4. Just not a lot of room to run the pipes compared to a t-56. In you're sold on long tubes I would just recommend going 1 3/4" and be done with it. If you wanted nice flowing standard style exhaust look at Dyno Don headers.

What torque arm are you using?

I also agree aftermarket Aluminum heads are very nice. Most places are pretty close in price. Just make sure you are pricing pairs some places list them each (1 head).

3" exhaust should be enough, but over doing an exhaust isn't going to hurt anything just more room to grow in the future.

 

get the 195cc versions of these
http://www.profilerperformance.com/r.../sbc-23-degree
for 500hp I'd go with 3.5" exhaust. Shorty headers will offer better ground clearance, long tubes with a 700R4 makes ground clearance impossible. Go with Dyno Don's for the headers.

 

I built my own cross member So I can cross my y pipe right after the tranny. I want to go with 200cc or larger. My cam has lots of duration and want to take advantage of it.

 

the problem is going along each side the trans pan between the pan and the frame rails. Your ground clearance is doomed to suck with an automatic and long tubes, there is no way to NOT run pipe UNDER the frame rails, period.

you want to 200cc heads but are using ported double humps? LOL whatever man. not sure I'm going to be able to help you....

 

I already have a TCI finned aluminum deep pan on it so my ground clearance already is very limited.

haha I mean when looking for new heads. Not currently. The double humps have a lot done (stainless oversized valves, hardened seats, angle milled .030", high lift springs) but I know they aren't going to flow the same as newer heads.

 

they wont flow anywhere even CLOSE to newer heads. AFR's are worth every cent. not just a name

 

Ground clearance is fine, you don't have to go over speed bumps.
LTs in from the bottom, no motor jacking, tired stock mounts, R-4, mufflex Y-pipe (so no Y-pipe fabbing) and a reducer, Y-pipe is all slip joints to it can be set how you want it.
-You WILL need a mini starter
-you WILL need a heated o2 ($20.99 on ebay)
-yes I have more pics

 

I'm not running o2 sensors right now but will need to get A/F guage to tune my carb to perfection.

I had to get a mini starter right after I put this motor in...Stock starter didn't like the 11.5:1 compression on the small ring gear flexplate.

 

Do you have a pic with a pop can or anything under the car for scale?

 

The closest pics I have right now to answer that. May take a can pic tmr.