Time to get serious

[El_Diablo]

1998 Chevy Malibu- small port 3100sfi, 4t40e 3.05FR

well i finally blew my 3100 all over route 28 at 70mph, nice smoke show and i got to see parts bouncing down the highway behind me... oh and some lady thought i was on fire so the truck showed up after they hard already passed me, they said they were looking for a fireball and didn't think it was me

anyways, its time to get serious about a 3500 swap, im trying to get a list together of things i need and i also need to know if this is even a bolt in swap with the exception of wiring

i know i need-
TCE crank sensor
DHP PT
TB adapter
TCE TB


now will the block mount up like my stock setup? what would/should i do for injectors? guessing maybe 3400 injectors and fuel rail with an aftermarket fpr (using the an adapters from the store) will be good enough in stock form? exhaust manifolds from an epsilon bu should fit my bu right?

ive searched and have been researching this for some time but i just wanna double check my work... other than the stuff i mentioned and wiring this should all bolt up though correct?

[silvergtjrad]

I think the 3400 w/a 3500 top end will be a better choice. Im not too familiar with engine swaps but I imagine the 3400 is a drop in pretty much. You are going to spend a lot more $$$ on the 3500 and parts to make it work for not THAT much more HP. Plus, the aftermarket for the 3500 isnt nearly as good as the 3400.

[El_Diablo]

either way pistons are custom, cams can swap between engines correct? and ben offers a ported top end.... eventually i would like to have a boosted stroker which is why i love the idea of a larger crank (offset grinding) and a factory oil squirter on 2 of the pistons

i hear a lot of guys talk about the fact that the aftermarket isnt as strong for the 3500 but honestly, how many few products are made for the 3500 than the 3400 short block? either way most of the stuff is custom and/or needs to be adapted

the 3500 seems to be a lil better designed so my hope is that i could get a lil more life out of it in the end aswell as a lil more power but if a 3500 is that much harder i may go with a 3400 (nearly a direct swap)

[PCGUY112887]

Soo why did it blow? What happened? Mods?

[Superdave]

go with the 3500, same cam choices as the 3400 and most of the aftermarket stuff like headers will fit fine.

It should bolt in like your 3100, there are a few mounting boss changes but that's the easy stuff. Your setup might not even use those bosses anyways.

[El_Diablo]

how did the bosses change? i dont have access to a welder right now and cant really do fab work with what tools i have available right now so that is pretty important to me....

anyone know if im forgetting anything?


basically the reason it blew was a spun bearing, ive honestly never seen an engine tear itself apart so fast but im trying not to think about it, lol, i love my car way to much

[bszopi]

Do a search ofr 3500 differences and you can look at comparison pictures Colin did between the 3500 and 3400.

[ForcedFirebird]

I think the 3400 w/a 3500 top end will be a better choice. Im not too familiar with engine swaps but I imagine the 3400 is a drop in pretty much. You are going to spend a lot more $$$ on the 3500 and parts to make it work for not THAT much more HP. Plus, the aftermarket for the 3500 isnt nearly as good as the 3400.

I've seen complete 3500 here in FL from $400 to $1500 depending on mileage. Of course I found them right after I paid for my 3.4 short-block, humph. Had I known, I could have got a tubular k member and the 3500 for the same price I bought the 3.4 short block and 3500 top end. I can't wait until the 3900 is a little more available.

[IsaacHayes]

The trans to engine mount bracket doesn't bolt quite up. AC compressor lower bolt doesn't fit quite right either. But some later 3400's have the AC issue too..

[El_Diablo]

so what changes need to be made to get these mounts to work?

is it as simple as enlongating the mount holes or making new ones? whats the deal? ive seen the pictures but its been some time now... still dont really have anything in front of me to compare with... its been a while

[IsaacHayes]

Check PCGUY's thread I think there are some pics of the bracket issues. IIRC one bolt hole can be elongated but the other one you need a whole new bracket if you want to use all the bolt holes... And the AC thing, well no solution that I know of.

[El_Diablo]

bottom a/c bolt goes into the oil pan i believe? i dont have a/c currently anyways though but it would be nice to swap it back in eventually but im sure if it came down to it i could prolly just use a 3500 unit?

[PCGUY112887]

The top 2 compressor bolts will bolt up, but the bottom will not. I haven't had any issues with my bottom bolt missing, nor has 3400Modified here on the forum.

As far as the trans to block mount, all will fit but the very bottom hole that is in the oil pan. I notched/grinded/etc the bolt holes bigger and got all of the bolts to fit but the bottom one. It was a bitch, a big bitch, but it does seem to work.

[El_Diablo]

so your running your a/c with just two bolts?

and what do you mean trans to block mount? the only actual engine mounts i believe are one or two on the passenger side (front of the block) IIRC, the rest are on the trans

do you mean the front trans mount thats located near the starter?

[IsaacHayes]

3400-modified's compressor is rattling because of the missing bottom bolt. And you can't swap a 3100/3400 pan on a 3500. You might be able to adapt the 3500 compressor if the lines that bolt to it will reach and bolt to your other stuff or get custom crimp job done on them.