LONG: Faster revs, not more revs...

[SCIV]

Why the target to maintain 11:1?

[Paulster2]

Under #4, you need to include a vacuum pump to evacuate the crank case. Without the extra air in there to push around, things tend to move faster.

As far as revving quicker, lighter is better. Where ever you can reduce weight safely, the quicker it will rev.

[GraniteBlueNNBS]

I would try a 6.0 or 6.2 block with a 4.8 crank for a bottom end assy with lightweight rods and pistons..

[beingblueeyes]

For an intake manifold you should chose ITB's
the most aggressive under drive i know of is this ati for ASA racing and its at 60% (useless for street use)
http://cgi.ebay.com/ebaymotors/ATI-9...item3cb3683b7b

[Lincolnman]

Do you have any idea what the guy's name on LS1tech is?
If by 377 SBC you are referring to a 400 block and 350 crank, yes - same idea.
I consider 11:1 to be the threshold for 91 octane compression. More compression generally means more power so I figured it made sense to run all the way up to the maximum practical limit there. Also, higher compression keeps the throttle response snappy so that it doesn't "hang" at higher RPM for an undue period of time. I have also read that you can modify your IAC to help drop RPM quickly after rev up, but I don't know how that works.
I understand the logic behind the vacuum pump, but wouldn't that mean more parasitic loss to running the pump than just directly moving the crankcase air?
Yeah, 6.0 or 6.2 was considered, I guess I said Gen III but I just meant Gen III+. I had thought about a 6.0 Darton sleeved block at 4.200" bore and either a stock or (reverse) offset ground 4.8 crank. Since the RPM limit is 7,500 I think that the stock crank should hold up fine, if offset ground I am less knowledgeable on their strength limit. Also, I have no idea what rods could be used with an offset grind. Some import part in a custom length?
ITBs? What does this mean, individual throttle bores? I see from a cursory search of Google images that most images for it appear to be velocity stacks and the like...
60% underdrive - WOW. Out of curiosity, is it useless for street because of inadequate cooling from the pump running too slow, inadequate charging for the same reason, or both?
Any thoughts on the small/light/light spring vs larger (and inherently heavier) valves and springs?
What about the dog bone vs double roller timing set?
...and will the 6 bolt heads work on a 4 bolt clock or not?
Thanks for the replies guys! Keep 'em coming!

[aj06bolt12r]

You are asking some very specific questions that relatively few people really know the decisive answers too. But considering this is a relatively small forum that focuses on moving heavy trucks around I doubt you will find much info here you didn't already know. With the acception of tuning info since you said you know nothing about that. Nelson or farmtruck seems to be the resident expert on that subject. However I would suggest you post this same question over on ls1 tech. They seem to like getting into deep theoretical discussions and there are alot of members over there that have knowledge to the point where I can barely follow what they are talking about. And I have been to auto diesel college and have been turning wrenches for a living since I was 15.

[beingblueeyes]

ITB= individual throttle body's (one per cylinder) here's a link to a Toyota v8 with itbs, notice the fast revs and throttle response
http://www.youtube.com/watch?v=Fm5k1ntJNBU
the 60% under drive would be useless because of both reasons, at a idle of 700 rpm your alt and water pump would be spinning 280 rpm and at highway speed (2000 rpm) every thing would be spinning at 800 rpm

[skeet]

i understand what youre wanting and trying to accomplish, i wont go in to detail but i will say as long as the valvetrain is as light as possible you would beable to spin the rpms up, i myself is building a 410 with a lunati pro series crank and rods and the lightess pistons found, with this in mind the topend has to match, light weight everything valves, rockers, springs, locks ( everything )


bottom line, its not cheap when you start hitting 8k rpms or above

[pl4yboy]

Do you have any idea what the guy's name on LS1tech is?
If by 377 SBC you are referring to a 400 block and 350 crank, yes - same idea.
I consider 11:1 to be the threshold for 91 octane compression. More compression generally means more power so I figured it made sense to run all the way up to the maximum practical limit there. Also, higher compression keeps the throttle response snappy so that it doesn't "hang" at higher RPM for an undue period of time. I have also read that you can modify your IAC to help drop RPM quickly after rev up, but I don't know how that works.
I understand the logic behind the vacuum pump, but wouldn't that mean more parasitic loss to running the pump than just directly moving the crankcase air?
Yeah, 6.0 or 6.2 was considered, I guess I said Gen III but I just meant Gen III+. I had thought about a 6.0 Darton sleeved block at 4.200" bore and either a stock or (reverse) offset ground 4.8 crank. Since the RPM limit is 7,500 I think that the stock crank should hold up fine, if offset ground I am less knowledgeable on their strength limit. Also, I have no idea what rods could be used with an offset grind. Some import part in a custom length?
ITBs? What does this mean, individual throttle bores? I see from a cursory search of Google images that most images for it appear to be velocity stacks and the like...
60% underdrive - WOW. Out of curiosity, is it useless for street because of inadequate cooling from the pump running too slow, inadequate charging for the same reason, or both?
Any thoughts on the small/light/light spring vs larger (and inherently heavier) valves and springs?
What about the dog bone vs double roller timing set?
...and will the 6 bolt heads work on a 4 bolt clock or not?
Thanks for the replies guys! Keep 'em coming!

Yes, the 400 block with 350 crank setup. RetroLSx is the one doing the motors. Here's a link to his forums. They aren't very active and I don't know his exact name on LS1tech.

[Lincolnman]

Sorry for the really technical questions, that's just the way my mind is wired. I understand that the forum is intended for trucks and that this build is contrary to the conventional thinking, especially considering the weight of your vehicles. I am not a member of LS1Tech (yet) and I joined over here because I ALSO own a 1993 K3500 that will be getting a Gen III+ motor (totally independent of this theory based build). I just thought that you guys would be a good place to begin asking. I have seen Nelson's name tossed around quite a bit on the forums, and when I do my truck I will likely look to him for a tune, but this thread is about different breed of build. I will look into LS1Tech more, though. "They seem to like getting into deep theoretical discussions and there are alot of members over there that have knowledge to the point where I can barely follow what they are talking about." I have had that feeling on other forums before, I know what you mean.
ITB - okay, so that was what I was thinking I just said bore rather than body. Thank you for the video link, I will look into ITB setups more. I had kind of guessed that the 60% under drive would be totally useless, but I thought I would ask anyway.
Skeet, you have the right idea, I think. I am just trying to hammer out ALL the potential little possibilities for a "total picture" build. (STILL THEORY ONLY!)
Thanks again, guys. I'm off to LS1Tech, but I'll be back!