When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Full disclosure, complete newbie when it comes to working on cars...I have been tinkering with my 76 L48 for the last few years (using this site as my bible). This winter I decided to dig a little deeper swap the stock cast iron intake with a Edelbrock 2101. I got the carb removed and am considering having it rebuilt while it is off (Lars still around?). I am at the point of removing the distributor but I think I have done enough research to ensure I have the rotor marked for reinstall. I am changing out the intake and carb gasket as well as buying a new thermostat housing. Anyone have any advice for other things I should consider replacing or looking at while the intake is off?
Lastly, probably a dumb question but what is the fitting the blue arrow below is pointing to on the intake? The hose is completely melted to it so I want to buy a new one. Just need to know the part number.
1. Blue thing is old heater hose. Use a pipe plug on new intake.
2. Do not use thee supplied intake end gaskets. Use some type of sealant.
3. Block of heat passages that go through heads. Some gaskets have built in blocks
4. Mark distributor body in relation to firewall and rotor in relation to dizzy
others will have more advice.
Thanks for the quick response.
1. You are saying that the hose going to this isn't used/needed? I just cut the hose right above the fitting right before I took this picture and planned on buying a new fitting to plug the hose in. I just didn't know the fitting.
2. I had heard this before. I think I am going to take your advice on that.
3. Interesting I had not heard this. I planned on buying the Felpro set: MS 90314-2. What is the reasoning for blocking it?
4. Makes sense!
3 what reasoning? They wanted to heat the carb up quick for cold idle emissions. Then the carb was too hot all the time after warm-up. Heater hose. Do you live where you will be using the heat?
Thanks for the quick response.
1. You are saying that the hose going to this isn't used/needed? I just cut the hose right above the fitting right before I took this picture and planned on buying a new fitting to plug the hose in. I just didn't know the fitting.
2. I had heard this before. I think I am going to take your advice on that.
3. Interesting I had not heard this. I planned on buying the Felpro set: MS 90314-2. What is the reasoning for blocking it?
4. Makes sense!
If you were using it before continue to use it on the new intake. Remove it from your steel intake and transfer over to the new intake or buy a new one. Threads are probably 1/2" npt and then whatever size hose your running for the male end.
On the china walls use The Right Stuff made by Permatex. (AutoZone) Its basically Permatex Black, but in a aerosol can, around $14. The difference between the old tube and the new stuff is; perfect control of laying down a perfect bead on the front and rear china wall. Clean china wall with Acetone.
On the intake to head gaskets, use Edelbrocks Gastinich (sp?) on both sides of the FelPros. Little harder to find (Summit) but its good stuff recommended by the intakes manufacturer. I like to apply that sealant to the bottom side only. Install gasket on head, insert a couple manifold bolts to align it and let set for several hrs then come back and apply the top coat. You can also apply a ring of RTV clear around the water ports of the head if you desire.
The Right Stuff sets up quickly, so be ready to go on that product.
On the waterneck, use a $20 gasket, not a $2 gasket. Otherwise you will be repeating this chore. Permatex makes a product called: Waterpump & Waterneck RTV.
Comes in a small tube (AutoZone) a little pricey, but is specific for Glycol applications.
On the heater hose fitting, NAPA has a aluminum unit bent at 90*. You can face that opening forward so the heater hose clears the valvecover. A good parts counter man will order that fitting for you. Use a thread sealant on that and just snug it enough to aim the port forward w/o leaking.
On the Eddy 2101, you will have to block off the EGR with a plate I believe.
And don't forget to order some nice ARP 12 pt intake bolts to compliment that new intake. Apply thread sealant to those also.
On my most recent intake swap, I took off the distributor cap, and bumped the starter until the rotor pointed straight forward. Real easy to remember how it needs to go back that way, then just hit it with a timing light when you go back together.
On the Eddy 2101, you will have to block off the EGR with a plate I believe.
And don't forget to order some nice ARP 12 pt intake bolts to compliment that new intake. Apply thread sealant to those also.
Good advice.
The 2101 doesn't have EGR so I won't have to plate it off. Regarding the bolts, honestly I have spent way to much time researching just bolts. Some like the 12 point, some feel it isn't worth the extra money, others say just focus on the bolt grade. So I haven't decided yet whether to go with expensive ones or just the $10 ones.
L48 needs more compression, more cam, true dual exhaust but not headers. Swapping an aluminum intake manifold ALONE is Not going to add hp-tq you'd notice.
Forum members should include in their profile an APPROXIMATE location where the car is maintained because the weather there can affect proper advice on some mods. While you might Not need a choke or exhaust xover in south Florida, you might need those in Michigan.
As said by others ... L48 needs cam & heads ... Vortec heads and a $100 jegs flat tappet cam & lifter kit, jegs Vortec intake $135, Vortec valve covers ... all roughly $1000-$1500 if bought new. OR ... OR
add a $135 jegs Vortec intake, pay a local machine shop $100 to open-finish fuel pump mount pad and you're at a solid 250-260 fwhp for under $1975 ... all brand new w/ GM warranty.
If you want more HP ... L31 Vortec already has OEM roller lifters so no need to $convert$ ... For another $500 or less: swap a bigger roller cam, LS6 valve springs & comp 787 retainers and it'll make right at 375-400 fwhp
L48 needs more compression, more cam, true dual exhaust but not headers. Swapping an aluminum intake manifold ALONE is Not going to add hp-tq you'd notice.
Forum members should include in their profile an APPROXIMATE location where the car is maintained because the weather there can affect proper advice on some mods. While you might Not need a choke or exhaust xover in south Florida, you might need those in Michigan.
As said by others ... L48 needs cam & heads ... Vortec heads and a $100 jegs flat tappet cam & lifter kit, jegs Vortec intake $135, Vortec valve covers ... all roughly $1000-$1500 if bought new. OR ... OR
add a $135 jegs Vortec intake, pay a local machine shop $100 to open-finish fuel pump mount pad and you're at a solid 250-260 fwhp for under $1975 ... all brand new w/ GM warranty.
If you want more HP ... L31 Vortec already has OEM roller lifters so no need to $convert$ ... For another $500 or less: swap a bigger roller cam, LS6 valve springs & comp 787 retainers and it'll make right at 375-400 fwhp
Great information. I live in Missouri so it may be helpful. Being a newbie, I didn't really know much about the exhaust crossover which makes these forums so nice. Regarding the performance, to be honest I am not trying to build a race car all in one winter. I am just doing little projects here and there as I have the time and money (and as I learn). I really am just trying to make the engine bay look a little nicer right now which means dumping the cast iron, paint peeling intake.
The 1205 Fel Pro works for the 2101 but I use the 1204 because it is thicker and crushes nice on stock heads....it will give you slightly more room to run a bead for the China rails front and back too.
Intake alone will show gains.....but intake, long tube headers, O-jet setup and distributor curve together will make it run like a different automobile.
The factory 4bbl intake is a cork.......the 2101 is a much better flowing unit.....no EGR and just nicer overall. The thing that makes me scratch my head is that the GM LT-1/DZ intake is an excellent piece.....they had this unit on the shelf and used it for like 4 years and nixed it.......they should have put it on everything.....it will run neck and neck with a Performer RPM up to 6000 rpm.....mill the divider and they are the same. You can still purchase that intake as a Holley Street Dominator....it was patterned off the GM piece.
If you want gains you can feel....do the intake, long tube header, curve the distributor and send the Q-jet to Lars for setup.........will make a ton of difference.
The 1205 Fel Pro works for the 2101 but I use the 1204 because it is thicker and crushes nice on stock heads....it will give you slightly more room to run a bead for the China rails front and back too.
Intake alone will show gains.....but intake, long tube headers, O-jet setup and distributor curve together will make it run like a different automobile.
The factory 4bbl intake is a cork.......the 2101 is a much better flowing unit.....no EGR and just nicer overall. The thing that makes me scratch my head is that the GM LT-1/DZ intake is an excellent piece.....they had this unit on the shelf and used it for like 4 years and nixed it.......they should have put it on everything.....it will run neck and neck with a Performer RPM up to 6000 rpm.....mill the divider and they are the same. You can still purchase that intake as a Holley Street Dominator....it was patterned off the GM piece.
If you want gains you can feel....do the intake, long tube header, curve the distributor and send the Q-jet to Lars for setup.........will make a ton of difference.
Jebby
The Felpro 1205 and 1204 have the exhaust crossover block. I was not planning on blocking it which is why I am using the Felpro MS 90314-2. It appears to be the same gasket but with the open crossover.
The whole idea with 12 pt bolts is it allows you to get a boxend wrench on there at a different angle when torqueing. A 6 pt bolt is more restrictive at getting the necessary wrench angle. And the 12 pt looks so much better, more professional than local hardware crap. Take a look at fasteners at Summit Racing, clicking on ARP "intake bolt set". They're really not that expensive and the quality is superb.
The exhaust crossover will come back to haunt you in the summer if you don't block it off. There has been hundreds of forum post about the carbs boiling over, vapor lock, how to keep the fuel bowls cool, etc, etc, etc. Block that extra heat off! Don't worry about a cold carb, who drives their Vette in the snow anyway?
The whole idea with 12 pt bolts is it allows you to get a boxend wrench on there at a different angle when torqueing. A 6 pt bolt is more restrictive at getting the necessary wrench angle. And the 12 pt looks so much better, more professional than local hardware crap. Take a look at fasteners at Summit Racing, clicking on ARP "intake bolt set". They're really not that expensive and the quality is superb.
The exhaust crossover will come back to haunt you in the summer if you don't block it off. There has been hundreds of forum post about the carbs boiling over, vapor lock, how to keep the fuel bowls cool, etc, etc, etc. Block that extra heat off! Don't worry about a cold carb, who drives their Vette in the snow anyway?
That makes sense regarding the bolts. I have also read posts where people talk the cons and issues they have ran into blocking it (rich fuel mixture and possible concerns with choke). I guess my line of thinking was that I never had a problem with it before so why fix what isn't broken. Then again I know that aluminum intake is very different than cast iron.
...I live in Missouri so it may be helpful. Being a newbie, I didn't really know much about the exhaust crossover which makes these forums so nice. Regarding the performance, to be honest I am not trying to build a race car all in one winter. I am just doing little projects here and there as I have the time and money (and as I learn). I really am just trying to make the engine bay look a little nicer right now which means dumping the cast iron, paint peeling intake.
Dozen years back I did a 3-month QE consult stint for a Tier 1 supplier at Farmington MO. Lots more ice, snow & cold than my native S Carolina. So I understand you want a nicer looking manifold & you prefer improvements in more affordable stages. The 2101 retains Xover runner under plenum and has a boss for divorced choke as on some QJet; I imagine you'd prefer to keep choke & plenum heater.
fyi ...Local circletrack 355" max rules require only 2101 in some classes but blocked Xover and choke delete permitted. Also, required 2bbl carb (Rochester or Holley) atop rule short adapter atop 2101. Flattops, Iron OE heads (76cc iron milled to rule minimum 70cc) No porting, solid flat tappet rule maximum .480" lift at valve. Most guys make about 350-370 fwhp on race gas; chassis setup & driver ability are KEY. (I have older SUN 404 & older Superflow SF-110 while local shop has both engine & chassis dyno)
Everyone's motor, regardless from OE passenger car to full-race, should have a good tune; everyone's starting point-basis should be optimized distributor curve and carb. No disagreement there.
You still don't understand the function of the crossover of hot exhaust air under your carb. It is to help warm up the carb while the choke is operating too. And that's all fine & dandy. But after several minutes the choke is done, the engine is warm, but that crossover continues to add heat under the carb. There is no "On & Off" switch. Its still putting hot gases under the carb continuously, even in the dog days of summer. Next thing you know, you are stranded on the side of the road with fuel percolating out of the carb.
If you read somewhere that blocking that off causes a rich condition, you better switch forums. Perhaps the choke stayed on a little longer but blocking the crossover does not cause a rich condition. Either the choke works correctly or it doesn't, regardless if the crossover is blocked.
You still don't understand the function of the crossover of hot exhaust air under your carb. It is to help warm up the carb while the choke is operating too. And that's all fine & dandy. But after several minutes the choke is done, the engine is warm, but that crossover continues to add heat under the carb. There is no "On & Off" switch. Its still putting hot gases under the carb continuously, even in the dog days of summer. Next thing you know, you are stranded on the side of the road with fuel percolating out of the carb.
If you read somewhere that blocking that off causes a rich condition, you better switch forums. Perhaps the choke stayed on a little longer but blocking the crossover does not cause a rich condition. Either the choke works correctly or it doesn't, regardless if the crossover is blocked.
Thanks, I guess I probably need to get a better working understanding of the choke and exhaust. I believe I don't have my heater riser any more. There was some debate here on the crossover blocking: https://www.corvetteforum.com/forums...-question.html
in the old days every one blocked the crossover on the intake once the engine was warmed up it was useless. down in the south you really didn't need a choke.
12-05-2018, 04:41 PM
Intake Manifold Swap - Looking for Input
