I have a 92Z 305 TPI that I want swap out for a 350. I want to stay fuel injected and keep my AC.

I was considering a LT1 but then I learned about HSR. I don't know which route to go. This will be my daily driver wih occasional stops to the strip.

With either block, I would like to reach at least 300rwhp but not sure how to get there. No NOS.

If I went with HSR should I look for a L98? Basically, I'm new to all this and need your advice to reach 300rwhp with either HSR or LT1. Which do you think is better? Which will cost less to accomplish? Please help.

Thanks.

 

300 RWHP should be easily attainable either way. Easier and cheaper with the HSR, since no adaptation (or at least very little....) would be required.

Yes the HSR will work fine on a L98. You'll need some other cam to get to that power level; I'd suggest a Comp "305" grind. Head porting will help greatly. Obviously you'll need all the usual work to the car itself, other than the motor, to get the most out of whatever motor you put in it, or even out of the motor that's there; headers, exhaust, gears, converter, chip tuning (NOT some off-the-shelf over over-the-phone chip), etc.

 

I pulled 310 rear wheel hp on a Dynojet dyno with the HSR, GM Hot Cam, and AFR 190 heads. Very reasonable target.

 

HSR is pretty similar to the LT1 intake as far as its advantages over TPI. There are differences, but I'm not sure how much difference there is.

John millican had a dyno with a LT1 intake on a L98. The L98 had a cam, headers, LT1 intake, full exhaust, and a aftermarket DFI system. It hit 299rwhp.

http://www.lt1intake.com/dyno.htm is the site where you can find mods/dyno charts of it.

An LT1 motor has better flowing heads, and already has an LT1 intake(duh). I'm pretty sure that with just headers/full exhaust it'll hit 300rwhp.

I'm not sure of the cost difference between the two. This is just what I've leared from reading the different threads out there over the past few years.

 

I would say closer to 275 but whats 25hp anyhow.
I say that because I think the average is 330rwhp or so with the hotcam and 1.6 rrs on an LT1.

300 fly wheel hp is very possible with just headers and exhaust on an LT1.

 

300 is surpassed with just headers and exhaust on an LT1....

 

I know the Vette was rated at 300 at the flywheel...and I know the f-body was 275...and I also know they are the same engine... So I won't argue with you over 300 being surpassed easily...

However I will if you mean in rwhp.

 

Thanks for your responses.

Does anyone know if the L98 block can be purchased new anywhere? I already have the TPI setup so I don't really need to buy the block with another but I guess I could always sell any spare parts.

I heard AFR195's work well with HSR but I think I read somewhere some porting is needed for it work. Is this true?

Also, I wanted to swap the 700R4 with a manual tranny. Any suggestion to what will bolt on easiest to the L98?

 

http://www.sdpc2000.com/cart.asp?act...id=514&pid=620

 

And whatever the LT1 puts down is surpassed with a set of spark plugs on an LS1...

 

And the price is also surpassed 3x over with the LS1

 

five7kid, thanks for that link.

Will my wiring harness for the 305 work with the 350?

 

As you start trying to reach the same power/tq output with an LT1, and the OptiSparks get replaced, the prices begin to even out...

While the spending may not eventually be equal, it sure isn't 3x or even 2x unless you have some real numbers you'd like to show...which I doubt...

 

You aren't changing anything that would keep it from working.

 

And you HAVE to replace the optispark? I've got almost 80K HARD miles on my LT1 with not a single optispark problem. The only reason I'm planning on replacing it is I'm going with a boosted setup with an aftermarket ECM, just seems logical to upgrade the ignition as well.

 

Oh yeah, now you went and did it...failure is imminent.

 

Being that headers are 2 - 3x what LT1 / Gen 1 headers are, rockers are more, cams are more, factor in the initial cost of about 3x, different mounts involved in a swap, the programming software for one costing 5x that of the equivalent for an LT1, it definetly begins to show. However this isnt to say a gen 3 cant be done on the cheap.... bwahahahahaha.......

 

Haha, wouldn't surprise me. Oh well, I only drive it about 2000 miles a year now since I'm away at school. No big deal.

 

I'm at 376rwhp with stock manifolds, heads, and rockers. I dropped $400 for the cam.

Stock LS1 rockers are roller fulcrum 1.7:1 ratio, same ones used in ASA crate engines for entire racing seasons, so aftermarket ones are generally not needed.

As for your header math:
JBA headers for LS1: $499 at Thunder Racing.
MAC headers for LS1: $349 "
Hooker headers for gen-1 SBC: $370 "

Where are you getting 2 - 3x price diff for headers?

You're making invalid, uneducated assumptions and trying (unsuccessfully) to pass them off as facts...kind of a "my car's slower, but it's cheaper" thing to help you feel better about it.

 

I saw this engine on eBay....
http://cgi.ebay.com/ebaymotors/ws/eB...ayphotohosting

The heads are from ProTopLine. Ever heard of them?

With a 700R4 w/3.73s do you think this block will et low 13s ?

 

go hsr itll give u better topend than a tpi setup and is more versatile than the lt1..ie..more parts. but heres an idea put tht on top of a set of protopline heads wth an Xtreme RPM LT1 cam

 

What parts?

 

heads mostly, there arent exactly a lot of choices of heads when it comes to an lt1. 2 the stand alone computer is more friendly to tuning...wider selection of cam profiles, i mean wth lts u hve to pritty much use Lt1-LT4 cams..correct?

 

Wrong on both accounts. There is now almost just as much of a wide range of parts for the LTx's as there are for SBC's.

 

well i didnt knw tht.. i still think an HSR motor would be better than an LT motor, maybe its jus preference but still wht bout the heads and ecm

 

I will admit, if you've already got a 350 block and heads, then yeah it would be much easier to do an HSR and keep the stock ECM. However, if I was starting fresh, I would go with an LT1 since prices have come down so much for used ones. You're starting off with a better engine, that has more horsepower to start with, that you can do everything to that you could the HSR motor. Same thing though, just my personal opinion.

 

the only 2 things i dun like bout the lt1s r the water flow and cam driven water pump, i mean it jus seems to be more ofa hassle and another reason i steer clear of em, but yea they r awesome motors rite off, and stonger components too. altho either case its not all tht hard to get 300hp.. one other thing for clif, think of the harness and ecm, will it be too big a project for u if u completely change it out

 

The first thing i want to see is the mac's installed into a thirdgen with an LS1, and a Y pipe, all bolted up and fitted, then lets see the jba's installed and factor in a Y pipe, oh your uneducated self forgot that part, while a set of hooker shorties with Y pipe will bolt right into the thirdgen and onto the LT1, Y pipe and all, you also say you dropped 400 for the cam, how about for the motor initially ? mounts ? programming ? Someone here is uneducated and not thinking properly, and i know it isnt me.......

 

You made the "2 - 3x" cost assertion, so bringing data to support that (invalid) point would be your responsibility. I've been answering with real numbers.

As for the headers, I didn't need them to get the rwhp I reported...stock manifolds.

As for the "uneducated" part of your spill, your punctuation and grammar says it all.

I'm done now, having recollections of the saying "don't argue with an idiot, they'll drag you down to their level and beat you with experience" and I'm seeing what the guy meant in your case.