going backwards need header advice

[pkj]

i am going about this project backwards and i need some help so it will all fit in the end. the truck is a 68 long fleet 307/3 speed.everything is stock. in about a year i will install a 400 sb with vortec heads, but i want to do my exhaust now. also later i will lower the truck 3/5. so nowing the future engine what header (coated) thru summit will work best for money. engine will be mild. torque being the #1 priorty, trans will be 5 or 6 speed manuel. since i am intreasted in torque what length header will be best. pipes will be 2 1/2 inch regular bends, H pipe, welded mufflers (not flowmaster) tailpipes exit at rear. i know the 307 will suffer some from this combo, but i want it to be tops for the 400. will the 307 header work on the 98 & up truck vortec head? what are best gaskets and bolts to use? i will advise exhaust shop of lowering and they should be abel to accomodate future lowering.thanks for all ideas and advice.

[crazy longhorn]

I dont think there are any diffs in the port size /boltpattern on the Vortec heads vs the old school Chev stuff....but Im not positive, so will leave it at that. Your headers will be available for the sb chev in , 1 1/2", 1 5/8", & 1 3/4", to fit the stock sb pattern. For a mild/street 383 or 406, the 1 5/8" headers are good enough, & they wont be too far out for the 307. Yes, as you know 2 1/2" pipe is way big for a 307 cube motor......but I totally understand the issue Set it up for the 406, be sure to run the H pipe, & you might think about cutting the tail pipes down in size(or do tundowns), to keep the little motor rollin. You can run 2 1/4 or 2 1/2" behind the mufflers , & the bends wont hurt you back there(away from the heat). I dont know where you are on budget(the evil we all hate!), but I would reccomend Hooker comps (1 5/8" tube/ 2 1/2" collector). These headers are reasonable as painted pcs(140-150) Jegs or Summit, but are pricey in Ceramic . Best of luck.... L

[ChevyDude]

Two steps forward on this one may just take you 8 steps back. Take some simple advise, Don't do a build this way! Things change and a year down the road, do something else with your money. I see red flags all over this one. JMHO.

[Sequoyah]

Originally Posted by ChevyDude

Two steps forward on this one may just take you 8 steps back. Take some simple advise, Don't do a build this way! Things change and a year down the road, do something else with your money. I see red flags all over this one. JMHO.

IMO, just wait...and do it once. Do other things in the meantime that won't potentially cause problems 'down the road'.

[pkj]

thanks. the reason i am going exhaust first is its free. i have a very good exhaust shop that has offered to do the system for me because of all the work i send them. i want to take advantage of this now. so i am looking for all your help on the headers i will supply. must be coated, work with 3/5 drop, fit the truck properly-15/8 long tube 3 inch collector, not leak. i like the hookers but they get to greedy with the coating cost. please help

[bryanw1968]

I would say it's not a big deal do do the exuast now if you were just going to rebuild the 307 down the road. But I agree, this is something you should wait on in my opinion. Once the truck is lowered and the new motor in, you may or may not be able to run long tube hedders. I personally have the Heddman Elite hedders and love them. They have a ball joint fitting at the collector and don't require a gasket. They are the 3/4 length size with 1 5/8 primaries.
On the 400 setup if you're looking for torque you could probably stick with that size. Just my .02 cents. Good luck!!

[Rdub]

hey.... I would say do what you're gonna do.... only you can judge your intentions or ability to carry through on a plan..... on the other hand, run this by your girlfriend or wife (whomever) .... I guarantee they will have an opinion on your ability to follow through with plans....

[ChevyDude]

Originally Posted by pkj

thanks. the reason i am going exhaust first is its free. i have a very good exhaust shop that has offered to do the system for me because of all the work i send them. i want to take advantage of this now. so i am looking for all your help on the headers i will supply. must be coated, work with 3/5 drop, fit the truck properly-15/8 long tube 3 inch collector, not leak. i like the hookers but they get to greedy with the coating cost. please help

Go Get some Summit coated headers, best bang for the buck. I had them on my 72' and currently on my 71'... and they fit...tight but they fit. My truck is an auto, so with 5 or 6 sp. linkage you may have to get creative. Mini Starter helped with room too. If you send them so much work, and it's free, why not wait for the right time when you have all the right stuff and do it once "for Free"...otherwise you will do it now "for free"...and then be needing it done again...at least part of it. I just wouldn't go about a build this way...free or not. Oh...and by the way...NOTHING is FREE in this world!

[pkj]

okay guys you are right. i have spoke with the exhaust shop and they say run the exhaust now with no headers and no big deal to build a new set of head pipes in future. that way i can still enjoy a good sounding system for a while. does that make more sense?

[ChevyDude]

Yes, Now go buy that High PO 400 SB....dress it all out, sparkley coated headers with *****in 6 sp behind it all.....and take lots of pics so we can all drool! LOL! Best of luck to you on your build, dude!!!

Alex