Hey, about to start pulling my 305 and putting 9n my 350 TBI from a chevy van. But I have a chance to get an LT1 cam, and some LT1 heads, I want to know if I should put them on there before dropping in this new engine. The engine should produce more horsepower than the 305, but I would rather put these mods on now rather than haing to change them later, when I get hungry for more power. Thank you!!

 

lt1 cam yes....
lt1 heads no... i dont think they can be used due to reverse flow cooling...

Shawn

if i remember right the lo5 has a peanut cam also...

 

Personally I would go with a bigger cam, but it's up to you. The heads can be made to work IIRC, but it is a major PITA.

 

The LT1 cam is probably a step up from the LO5 cam, but is VERY mild for a 350. Is the LT1 cam free or very cheap?

Don't even bother with the heads, way too much effort.

 

Trade the heads for some L98 aluminum or Vortec heads.

Steve

 

LT1 Cam is free, but if I should go bigger, what do you suggest? and where could I get some L98 heads, or aluminum vortec?

 

Just don't forget that you just can't swap the LT1 cam in there. The LO5's didn't come with roller setups. So if your 305 is at least 87 or later, you'll have to swap all the roller stuff over too.

Tom

 

you can definatly use the lt1 heads i cant find the link to where i read it, however it does require a little machine work the flow the better then the zz4 head. do a search on google and read up on it and i will post a link if i find it.

later
graham

 

only the truck lo5's were non roller... lo5 in caprice's were roller IIRC...

shawn

 

I think you've got it backwards. You either want aluminum L98 heads or L31 vortec heads. The only gm aluminum vortec head is their new fastburn heads and there $1200.00 a set. And no you can't use the LT1 heads with out major modifications.

Steve

 

i've been reading through some posts tonight and was thinking...(they need a smiley face w/smoke coming out of his ears...lol)

1) Where's the power-band of the LT-4 hot cam? If people have successfully transplanted it into a 350 TBI setup, wouldn't it make sense to accomplany it with a good bottom end? I notice a lot of conversation focuses on heads, but for really really cheap bucks ($200 or so) you can get a set of PM chevy LT1 Rods that'll really strengthen a reciprocating assembly. Balance the puppy for another $200 and you can spin up to 5,500 (6,000 if you wanna push it) without worrying any.

2) How many of you guys have encountered problems with the Vortec heads yet? I've heard of the bolt pattern causing sealing problems, and also that they don't like high-lift cams (such as the LT4 i'd assume) because the retainers hit the guides. I guess people like them, but they're still a late casting with thin walls... I'd much sooner go for a set of Dart or World Products Sportsman II Heads. for around $800 you get 2.02 / 1.60 swirl polished valves, rocker studs, guide plates, and i think 180 or 200 cc runners AND EGR provision too! lol. When i worked at the race-shop we turned out a LOT of drag or street motors and they all had dart or sportsman heads on them (one of the cars made i think 500 or 600 10 second runs before even a rebuild!). They're good for porting too (lotsa meat).

I've been studying the 350/TBI ideal for a while now, and i'm kinda thinking of how far it can be pushed. The vast majority of us are running around 300-350hp, but I'm thinking that this winter (provided this summer's tuning goes well) my girl will go under the knife again. An LT4 cam, roller rockers, sportsman heads, and some tweaking and i bet i'll get 400+ easy. I just wanna beat my dad's hi dollar 5.0 mustang actually. haha

Tyguy

 

Well I found the finally found the page I was talking about. http://www.lt1intake.com/LT1_retrofit.htm If you’re getting a good deal on the heads I would seriously look into doing this. Now I'm not saying to go into this blindly, however I looks very promising. If you find out anything about this retro fit let me know I really don’t have the time to research this right at this moment.

To steve8586iroc I'm not trying to be smug or come across in a bad manor, but one thing I hate about message boards in general, is people that just say it can’t be done or it’s just not feasible. In sept of last year I came across an incredible deal on a brand new cobra motor (yes I am a mustang owner it’s a blk 02 gt). I posted a question on a mustang msg board about swapping it in my car. You wouldn't believe the comments I got, everything from you need a new tranny to having to swap the k member and not to mention the “It wouldn’t be cost effective" all from people that didn’t have a clue. Can you guess what the most populer swap is now for a new mustang.......... anyway I’m sorry for the long response and no disrespect to steve8586iroc was meant to help people think a little more creatively.

 

Fastrucken, I understand where your coming from and appreciate the approach taken to back me down(or anyone else that has a negitive attitude on mods), but after reading the article linked in your post I would have to stick to my guns on this one. I never sad impossible just impractical for the average joe. Now if you own or have access to a machine shop and know how to use the tools then it would be a different story. You know the saying" Anythings possible if you try hard enough".

Steve

 

Im glad you didnt take it badly I wasnt trying to ruin MDFBody's thred. Since you read the article what about using the intake for the lt1 as well if he can get the heads and cam at a good price maybe he could get the intake as well since most of the machine work was req to put an older manifold on the lt1 heads. Then he could have a pretty nasty little small block a 350 and more horsepower sholdnt be that hard to reach then with the old weesy tbi stuff

 

I don't think anybody makes a fourbarrel intake for LT1 heads yet. I'm not saying there isn't one just I have never heard of one.
Sounds like a good idea though.

Steve

 

The Lt1 heads are great but they aren't as good as a set of stock vortec heads or even the cast iron Lt1 heads. For some reason the aluminum heads in general from GM aren't all that great. The aluminum vette heads aren't that great either. The exhaust ports are better....anyways, the aluminum lt1 heads are still better than the aluminum vette heads.
http://www.sallee-chevrolet.com/Inta...24502592gm.gif
How's that. It's a carb/tbi intake for gen 2 Lt1 engines 1991 and newer. FYI, it's been around for years .
Getting those Lt1 heads onto a gen one block requires a LOT of work. Maybe not money but definatly time. Too much effort but that's what everybody said for vortec heads .

 

Comparing world products S/R Torquer heads , Vortec , and L98,Which heads flow the most?

 

:lala:

Ahahahahahahahahahahah

 

Pablo - instead of laughing perhaps you'd like to explain your disagreement?

The LT4 Cam runs .476 intake/.480 exhaust lift, with a duration of 203 degrees intake/210 degrees exhaust. Right now I'm only running .440/.454 lift and 212/216 dur with a Compu-Cam and I'm fairly confident that I'm at least around 320hp. The Vortec crate motor is 330hp and has a LOT LESS lift than the LT4 cam. Wouldn't there be a power gain with the LT4 cam?

The roller rockers and sportsman heads explain themselves. The hp I'm running is on a set of properly ported late model heads with stamped rocker arms. Nothing fancy so I dont see how there couldn't be gains with those add ons. And the heads are good for it too despite the clout of the Vortecs. I've seen drag cars run 9's with a well prepped set of sportsman heads on a 383 - and the owner didn't have to worry about cracking his thin-heads too.


Here's how my guesstimation of my hp breaks down (since I dont have #'s yet)

260hp 8.5:1 compression boat motor
+70 hp between: port matched/polished heads, thin exhaust valves, hi-flow holley intake, higher lift cam, higher compression (10:1), higher flowing induction (670 cfm tbi), free flowing exhaust, open element, no A/C, ect ect.
I may be guessing, but 320ish-hp doesn't sound too off the wall. The hp limit of TBI is limited only by how much cam u can run.

 

Um, don't chevy marine blocks rotate the opposite direction? How the heck did you get that to work?

 

i guess not - at least not mine. I got it from a buddy at work. His kid took the boat out and floated a valve. lol


Ty