Guest goldraven Posted February 20, 2004 Share Posted February 20, 2004 ok, so i got my lt1 exhaust manifolds in yesterday. went up to the car today and they will not bolt up to the block. The engine i have is from a 88 pick-up. The distance between all the header bolt holes on my block is 17.5''. the lt1s wont fit. what is the deal? What is the solution? will i have to make a custom header afterall, or is there another set of rare headers that will work for the engine i have? any insight is greatly appreciated. thanks guys once again, Nick Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted February 20, 2004 Share Posted February 20, 2004 arent the heads from LT1 and 1st gen not the same? I dont think the 88 Chevy would be an LT1. I have an 88 350 in my truck and it's 1st gen style. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted February 20, 2004 Share Posted February 20, 2004 They should work. I used pre-LT1 header flanges on my LT1 so it makes sense that the reverse would work? Quote Link to comment Share on other sites More sharing options...
Guest goldraven Posted February 20, 2004 Share Posted February 20, 2004 i was told they do work. I am dreading that the place i baught the engine from mislabeled it. Quote Link to comment Share on other sites More sharing options...
wheelman Posted February 21, 2004 Share Posted February 21, 2004 Nic, I think I know what the problem is, maybe?? I just looked at the heads on my LT1, the engine those manifolds came from. There are 2 extra bolt holes that are in front of and behind the normal mounting holes. The headers I bought don't mount to these extra holes but the original manifolds did. The measured distance between the 2 outside (furthest apart) bolt holes is 19 inches, the distance you measured on your heads is from what are the normal 1st gen mounting holes. Unfortunately I don't think there is a solution to this unless it would be possible to drill though the mounting flange at the correct location to mate up with your existing bolt holes or drill and tap your heads at the correct location. I don't think either one is worth the cost for those manifolds. I'm thinking you want to find yourself a set of rams horn manifolds to use on that engine. They are shown in the JTR manual. I'm the person who sold those to you, if you are willing to cover the shipping both directions I'll refund your money. It cost me about $17.00 to ship them based on the package size and weight. Ken W. Quote Link to comment Share on other sites More sharing options...
Guest goldraven Posted February 21, 2004 Share Posted February 21, 2004 i would use the "ram horn" style of headers if they would fit. these are the pics of the distance that there is between my block and power steering box. any other creative ideas that might work on getting a header in there? Quote Link to comment Share on other sites More sharing options...
wheelman Posted February 21, 2004 Share Posted February 21, 2004 Do you have the 7th edition of the JTR manual? On page 14-7 it shows a manifold from a 1980s series Camaro, Caprice and Monte Carlo that might work for you. Other than that the only other suggestion I have is to look at 80LT1's web site. I think he either custom built a header or used a header on the passenger side and a manifold on the driver's side. You might try PMing him as well, He already solved this problem and should have some pointers for you. His engine is an LT1 so his solution may not work but it's worth a try. Ken W. Quote Link to comment Share on other sites More sharing options...
Guest goldraven Posted February 21, 2004 Share Posted February 21, 2004 i do not have the JTR manual. but i did a search on ebaymotors. is this the manifold you are talking about wheelman? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33632&item=2461240266 [/url] Quote Link to comment Share on other sites More sharing options...
wheelman Posted February 21, 2004 Share Posted February 21, 2004 Nic, I looked at that ebay listing and can't see the picture well enough to say if it's the correct one or not. If your really interested in them I'd email the guy asking for some better pictures and that he measure the distance between all the bolt holes for you. I'm pretty sure the passenger side one is not going to fit based on that picture though. I don't think it will clear the starter. I don't know for sure if Pontiac was using the same V8 for the firebird at that point as the Chevy used for the Camaro but I think so. Sorry about all this hassle man, I know how it can be to try and find the right part and always come up short. Ken W. Quote Link to comment Share on other sites More sharing options...
wheelman Posted February 21, 2004 Share Posted February 21, 2004 Nic, I did a little searching on the net and found this picture, it's a 1980 Camaro drivers side manifold. Will this work?? I think it might clear your steering box. Ken W. edit: Here is the link to the online store where I found it. http://www.1aauto.com/1A/ExhaustManifolds/-/-/PLP1390114 Quote Link to comment Share on other sites More sharing options...
Guest goldraven Posted February 21, 2004 Share Posted February 21, 2004 yeah, i was looking at that same kind of header...at this point i'm willing to give it a shot. but from a first glance it looks like it might work. i've already emailed the guy, waiting for a response. Quote Link to comment Share on other sites More sharing options...
Guest goldraven Posted February 27, 2004 Share Posted February 27, 2004 yeah, those '80s firebird/camaro manifolds are 19'', just like the LT1s that wont fit my car. the funking dealership here told me they would work. but clearly it is the wrong measurement. Nick Edit: I had an idea, is there any place that makes adaptor plates to fit the 19'' exhaust manifolds from these camaros/firebirds to my block that needs 17.5'' bolt pattern? how hard do you think it would be to make an adaptor plate? any problems that i'm not seeing with this idea please tell me. Nick Quote Link to comment Share on other sites More sharing options...
Guest goldraven Posted February 27, 2004 Share Posted February 27, 2004 New plan! I was looking at the exhaust manifolds from the LT1 and LS1. The port holes still line up. its just the bolt holes on either end of the exhaust manifolds that extend too far. there is alot of metal to work with on the ends of these manifolds...im going to try and drill a bolt hole in the correct place on the LS1 exhaust manifold(simply because it has just slightly more metal to work with) so that a header bolt can go through the new hole into the existing hole in the block. if this doesnt work i can still make an adaptor plate to make it fit. I'll post pics to keep you guys updated on how this is going. Nick Quote Link to comment Share on other sites More sharing options...
labrat Posted March 6, 2004 Share Posted March 6, 2004 I'm having the same trouble on my 280ZX. The rams horn manifold works fine on the passenger side, but the only manifold that will clear the power steering box on the driver's side blocks the dipstick hole on my early block. If you have a later model block with passenger side dipstick, check the buy/sell/trade forum for my post and send me a PM. I'll take a $10.00 site donation plus shipping for the pair. Guaranteed to fit perfect (ran them for a year) But I dont like the idea of no dipstick. BTW, I ended up buying a custom header kit with flanges, j-bends, and collectors. Gonna try and weld me up a pair of shorty headers(don't know how successful I'll be...). Bill Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted March 11, 2004 Share Posted March 11, 2004 This is probably old news to you guys, but I'll beat this horse one more time just to make sure it is dead! The manifold from a mid 70's Chevy should work. Casting #364747. I think mine was from a '78 El Camino, but there were a lot of models that used this manifold. Note the driver side dipstick. I might have had to bend the tube in slightly to make it work. There are also flexible dipsticks on the market too. Lokar I think makes them. Quote Link to comment Share on other sites More sharing options...
Guest BillV Posted March 30, 2004 Share Posted March 30, 2004 I know this is really late,but there are adapters to mount the LT1 manifolds, or later model manifolds. It is a plate with the last bolt countersunk, and an extra bolt hole on the end, the only difference is the last bolt hole. I have a ser if you are interested. I was going to use them on a S10, but the manifolds dumped in the wrong place. Quote Link to comment Share on other sites More sharing options...
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