I've inherited an '87 Wrangler. It originally had a 2.5l engine. It's had an engine swap and now has a 6cyl. 1- How can I tell whether the engine is a 4.2l or a 4.0l? There is no mechanical fuel pump boss on the block, but from what I can determine the 4.2 was available with F.I. for a couple of years and didn't have the boss in those years. The intake manifold looks like an OEM aluminum 2bbl manifold. Both bores are the same size. There is a circular electric heating element in the bottom of the manifold held in with 3 bolts. A Carter 2bbl for a 273/318 fits on it perfectly, It had a Motorcraft progressive 2bbl on it, but the mounting bolt holes were totally buggered to make it fit. The exhaust "manifold" is a tubular header style with round ports and looks OEM. Any ideas on exactly what I might have? Thanks.