Vortec conversion question (not the usual)

[jjorgensen52]

So, since I am swapping the GT to vortecs and retaining the CMPI manifold, I have a new question. We were originally going to mate the old and new manifolds, but the fuel injection system differences were posing some major problems.

Can a LB4 / L35 style manifold be redrilled to the vortec bolt pattern, instead of vice versa? I realize that the bolts are probably going to be right at the edge of the base plate, but making a piece to distribute the load isn't a problem

 

[MikeRenz]

Re: Vortec conversion question (not the usual)

got pics of the intake in question?

 

[jjorgensen52]

Re: Vortec conversion question (not the usual)

I haven't got any good ones but here are a few of the same kind from SonomaGTLover (fitted against a set of redrilled vortecs)

 

[blk00z28]

Re: Vortec conversion question (not the usual)

I'm sure anything can be done with either enough money, or time.

What might have to happen would be the valve covers would be angled to clear the added metal put onto the intake, which might cause some clearance problems with the rockers/springs. Or at the min. notched a bit. :dunno:

Good luck with that though.

 

[MikeRenz]

Re: Vortec conversion question (not the usual)

that can definitely be done. I'm sure the shop i use would be willing to do it if you don't have someone able.

 

[jjorgensen52]

Re: Vortec conversion question (not the usual)

that can definitely be done. I'm sure the shop i use would be willing to do it if you don't have someone able.

Thats what I thought as well. After taking it to my local machinist and having him look at it, he seemed to think I would be spending less money and effort if I got a sheetmetal manifold. I didn't think that was the case, but what to do. It looks to me like the worst spot would be the 3rd bolt on the drivers side because it is inside the plenum, but there is definitely enough material there to use a longer bolt and come down from above. ( it would be a little tight on the fuel supply line, but doable)

I'd consider sending it down to you if they aren't going to charge me a fortune to do it

 

[MikeRenz]

Re: Vortec conversion question (not the usual)

it would probably be $375-$450 to do...but they do nice clean, stock looking work.

 

[jjorgensen52]

Re: Vortec conversion question (not the usual)

it would probably be $375-$450 to do...but they do nice clean, stock looking work.

Heck, it'd cost me that to have the manifold welded and heads redrilled to do it the other way. I would vastly prefer to do it this way (partly because I've got a nearly new long block and I don't want to pull the heads off if I don't need to).

I've also been trying to limit the mods I make to the engine... The only parts by the end that I expect to have modified are the manifold and the A/C bracket.

 

[MikeRenz]

Re: Vortec conversion question (not the usual)

yea, its the same basic work as what we do to the syty lower intake. I'm speculating on the cost...but pretty sure thats the ball park. The only issue it the bolt holes. They might have an intake at the shop, i'll call them today if i get a chance.

 

[jjorgensen52]

Re: Vortec conversion question (not the usual)

yea, its the same basic work as what we do to the syty lower intake. I'm speculating on the cost...but pretty sure thats the ball park. The only issue it the bolt holes. They might have an intake at the shop, i'll call them today if i get a chance.

Alright Mike, thanks in advance

 

[jjorgensen52]

Re: Vortec conversion question (not the usual)

Or, since I am wanting to get this done within the next week, has anyone ever redrilled the heads while they were mounted on the motor?

 

[MikeRenz]

Re: Vortec conversion question (not the usual)

don't do it. you will drill into the water jackets and undoubtedly add metal to your system.

 

[MikeRenz]

Re: Vortec conversion question (not the usual)

and besides its not something you should be doing w/ your hand held drill

 

[jjorgensen52]

Re: Vortec conversion question (not the usual)

That is what I figured :lol: ... yeah, oh well I'm just typing without thinking because I'm trying to get everything done