Different intakes for different engines/heads
 

Ok guys I've got a 71 GMC K2500 with a 350... But the 350 seems to be a "Target Master" from the 80s or 90s... However it does have an original cast iron spreadbore intake (which is leaking from the front coolant "pass through/chamber" (only visible once engine has heated up and is currently just seaping. I plan on replacing the Eddy 1406 with either an original (rebuilt) Q-Jet or a spreadbore Holley 80555C. Question is... Edelbrock performer 2101 (old style mid 60s heads to mid 80s)or Edelbrock 2104 designed for 80s-?90s heads? I'm not 100 percent sure exactly and can't find too much info on the internet... My "search" skills are lacking. How do I tell what I need? My understanding is there is a different "slant" on the center bolts? I honestly don't know. Or can anyone suggest a good intake for a spreadbore? Any help would be appreciated.

Re: Different intakes for different engines/heads
 

I only know of the 2 bolt patterns on a small block, the old style where the bolt is "angled" but square to the cylinder head (so its angled in the intake 55-early 90s) then the later Vortec style where the bolt goes in vertically up and down if looing at the front of the engine, the intake has raised and milled flat areas to make up the angle difference. Some heads during the switch I think were drilled for both patterns, not sure I dont really mess with later model small blocks. You would have to pull your intake to see if that is the case, but if you currently have an original 70s intake on the motor then its using the older style pattern. So a good old performer should fit.

Re: Different intakes for different engines/heads
 

That is what I was thinking just kinda wanted to have parts on hand before I tear in to it... There is a guy near me selling a Performer 2104 for a decent price but I don't want to pounce if I'm going to end up trying to sell it later... All I can find about the 2104 is what Edelbrock has on its website "Edelbrock part #2104 Performer intake manifold is designed for street 262-400 c.i.d. Chevy V8's that have heads with canted center bolt holes, 1987-1995."

Re: Different intakes for different engines/heads
 

So I did a little digging as well on google as it sparked my curiosity, yeah that canted center bolt patter is different than both the vertical and original style. Never knew that myself, but I have never swapped a manifold on that era of small block.

Re: Different intakes for different engines/heads
 

Get a 2701 or generic

Re: Different intakes for different engines/heads
 

Gonna throw another monkey wrench in the works... A guy on my block has a Weiand 8004 (spreadbore) he wants $40 for... But it has a chunk missing out of the distributor "lock" bolt hole(just the lip) ... Other than that it looks new(ish)... *rolls eyes*... My head hurts. :oP

Re: Different intakes for different engines/heads
 

Do you mean a 2601? I don't see that the 2701 comes in a spreadbore.

Re: Different intakes for different engines/heads
 

Sorry, misread you were going spreadbore.

Re: Different intakes for different engines/heads
 

Original Chevy GEN I SBCs are all the same. Vortecs came out in '96 and have a different pattern. Edelbrock has "dual pattern" intakes that will fit both heads. GEN IIs are an outlier :)

I think you're looking for this one; smart investment accepting both spread- and square-bore carbs and fitting earlier heads.

https://www.edelbrock.com/performer-...fold-2101.html

Would definitely steer you towards the Holley spreadbore; if you're going to go rebuilt Q-Jet then use a reputable source - most are junk.

With SMI closed down, only https://cliffshighperformance.com/ remains IMHO. And they're only selling kits and refurbing the throttle body now I think...

Re: Different intakes for different engines/heads
 

If you remove late LT1 there are basically 2 1/2 bolt patterns for SB Chevy intakes.

Style 1-1955-1986 they are all the same with inner bolts at the same angle as the outers. This also continued with the "Targetmaster" 350 crate engines to the end and aluminum heads on Corvettes until 1991. Intakes through 1968 have provisions for oil fill in the front of the intake. There are factory aluminum and cast iron versions to fit 2bbl, Holley, Q-jet, and early 4-bbl carbs (and early mechanical fuel injection as well as Tuned Port EFI).

Style 1 1/2-1987-1995 center valve cover bolt heads have the same pattern but the center bolts on each side are vertical instead of at an angle with the rest. Crate engines with center bolt (non-Vortec) valve cover heads also have this pattern. There are factory aluminum and maybe cast iron versions to fit Q-jet and TBI (as well as F-body Tuned Port EFI).

I am told that you can go back and forth with these with a wedge washer and hogging out the center holes but I have not personally done one.

Style 2-1996-2000 Vortec heads have a unique pattern with all vertical bolts. The only factory intake is plastic for Vortec EFI.

Re: Different intakes for different engines/heads
 

https://quadrajetpower.com/

For high quality quadrajet parts and rebuilds.

Re: Different intakes for different engines/heads
 

The easiest way to tell the vortec intakes is they have 2 bolts at the front and rear on both sides and non in the center of the intake at all. There are several aftermarket intakes that are drilled for either style head. I’ve got a few of them.

Re: Different intakes for different engines/heads
 

Sweet, thank you! 👍

Re: Different intakes for different engines/heads
 

Excellent information and thank you. 👍

Re: Different intakes for different engines/heads
 

Ok guys narrowed it down to I believe 3 options...
1)Edelbrock 2101 first choices, hard to find used
2)Weiand 8004, 2 available near me under $100
3) Holley "Street Dominator" 300-28z, less desirable... But free. All dual plane spreadbore.
What are your suggestions/ comments?

Re: Different intakes for different engines/heads
 

I have a Weiand 8004 on my Mr Goodwrench 350 [c. 1998] in my '71 GMC Jimmy. I have a Carter AFB 9635S [ = an Edelbrock 1405] on an Offenhauser spreadbore adapter.
I like it, but I wouldn't like one with a chunk out of it.
:gmc2:

Re: Different intakes for different engines/heads
 

I found another one that looks fine (no chunks missing) near me for $40, just needs a cleaning

Re: Different intakes for different engines/heads
 

I think I paid over a hundred, new, retail, at the Hot Rod Shop about 25 years ago.

Re: Different intakes for different engines/heads
 

Don't get me wrong this one ain't gonna win any beauty pagents but it looks like it has just been sitting on a shelf and I can't complain about the price... Vs my cracked/seeping one.

Re: Different intakes for different engines/heads
 

I rebuilt a 292 L6 in 2005. I took my 4 Bbl Offy intake in to my machinist's and he hot tanked it. It cleaned up nice. Try that or a dry soda blast. Almost pure aluminum, should shine up bright.

Re: Different intakes for different engines/heads
 

Good advice, will do. 👍